Document ZJNGo9XKLvKeo86EwmJkjnZOJ
EXHIBIT p WCD-32
C ; D E P A R T M E N T OF MINERAL EXPLOITATION
U N I V E R S I T Y C O L L E G E : CARDIFF
J&J-0060642
AN EXAMINATION OF ITALIAN MINE SAMPLES AND RELEVANT POWDERS
This document represents the completion report of the Italian mine samples and other powders supplied by Johnson and Johnson, Cosham, Portsmouth, to the Department of Mineral Exploitation. The persons involved in the examination of the material reported here were:
Mr. J. Lightfoot Mr. G.A. Kingston Dr. F.D. Pooley
Received: 8th September 1972
J&J-0060643
REPORT OF INVESTIGATION OF ITALIAN MINE SAMPLES AND' RELATED POWDERS
Introduction
O
Talc is hydrated magnesium silicate (Mg3Sit,Oi 0(OH) 2) which can occur in a number of forms In its compact form it is known as steaiite or soapstone. The form normally employed for toilet purposes is soft and very friable in character. It is mined in many parts of the world including the U.S.A., Canada, France, Italy, Norway and India, as well as several other countries. It occurs in both a flaky and lath like form and the chief deposits occur in altered magnesia-rich calcareous rocks such as dolomite, marble, and magnesian limestone. The purest talc deposits occur in association with dolomite and marble. Talc also occurs in altered basic rocks such as serpentines and again as thin beds in mica schists. Commercial talcs contain a number of related mineral Impurities. They may include antigorite {hydrated magnesium silicate) magnesite or members of the magnesite-chalybite series of carbonates, dolomite {calcium magnesium carbonate), tremolite and actinolite {calcium, iron magnesium silicates), chlorites (magnesium aluminium iron silicates) and other minor minerals such as the sulphides and spinels.
The hand specimens examined in this report were collected at the Italian, mine and do not represent an average collection of specimens of material being produced at the mine. The specimens were collected with the intention of sampling those areas with obvious non talc mineral inclusions. Specimens were retained which showed differences in physical appearance, i.e. fibrous, flakey, massive and powdery in texture. Specimens of ore in which colour variation was observed were also collected. In general the colour of the talc ore varied from grey through white to a light green colour. Obvious inclusions in the talc ore itself were retained and a careful search at the various sample locations in the talc seam was performed for fibrous amphibole minerals.
Specimens of the hanging and footwall were also collected to assess their mineral content as these were likely sources of ore contamination, although the method of mining which consisted of hand filling methods precluded any gross contam ination of' the ore.
The hand specimens, have been, where possible, prepared
for examination by the optical microscope and both polished
blocks and thin sections of material have been employed.
Representative fractions of all hand specimens have been
reduced to powder form and subjected to powder X-ray diffrac
tion examination. (The representative powdered samples also
form the samples for morphological examination by the electron
microscope.
'
J&J-0060644
The list of samples obtained from the Italian mie are given in Tables 1 and 2 and throughout this report the samples are referred to by the preceding code number for each specimen.
The objective of the examination has been mainly to es tablish the major minerals which.occur in association with talc at. the Italian mine. In particular to look, at the association of these minerals with the talc and especially those minerals which are of the same family as the commercial asbestos minerals, i.e. the amphiboles and serpentines.
The objective of the optical examination has been to establish textural and mineral relationship and not to quantify the phases occurring in each hand specimen. X-ray work has been aimed at establishing the minerals observed by optical ' means and to produce reference patterns for future investiga tion together with computed data from pattern measurement.
Electron microscope work has been selective in nature and performed on the finer fraction of the powdered specimens. Its aim has been to describe the morphology of the particles produced by comminution of the hand specimens and to investi gate any obvious structural information which might be of use in identification of individual mineral particles.
Representative data obtained from the various examinations are included in the following report.
i
J&J-0060645
Code No. 1 .1 . 1 .2 . 1.3. r.4. X o5 o 1 .6. 1.7. 1 .8 . 1.9. 1 .10.
loll.
1 .12. X.13.
1.14. 1.15. 1.16. 1.17. 1.18. 1.19. 1.20. 1.21. 1 .22. 1.23. X.24. 1.25. 1.26. 1.27.
TABLE 1
LIST OF ITALIAN MINE SAMPLES
Description
Talc from footwall contact
Sorting pieces (with, obvious colour differences)
Coloured talc (green.)
Face 10 sample with obvious amphibole inclusion.
General ore
Suspected Quartz sample Mica schist specimen
#
Massive talc
Grey talc 1st face
Granular talc sample
Carbonate and talc
Footwall sample? Amphibolite
Inclusion showing passage into talc bottom transit.
Inclusion In talc seam face 4, middle of seam.
Talc footwall contact
Inclusion from face 1,
Footwall rock, sample
Face 3 carbonate/talc sample
Tremolite/quartz/talc sample
Amphibole sample from Gianna 7vol 1212
Inclusion from face 2.
Carbonate/talc sample
Black, gneiss 2 ft below talc seam i
Talg next to carbonate face 2.
Footwall limestone
Talc inclusions
Lithological inclusions face 1
J&J-00B0646
Table 1 Continued
4
Code No.
Description
1.28. 1.29. 1.30. I.31.' 1.32. 1.33. 1.34. 1.35. .36. 1.37. 1.38. Ii 39. 1.40. 1.41 1.42. ,.43. 1.44. 1.45. Xo 46 o
Quartz/talc sample
Sample 6 footwall
_--
Quartz/Carbonate/talc sample
Black inclusion ace 1
Pace 2 inclusion from base of talc
Talc from lower left end of working
Marble/tunnel wall
Massive carbonate from rear end of working
Grey talc specimen
Carbonate in talc inclusion
Pyrite/talc specimen
5" -> 0 pieces from crusher
Platey talc
Face 2, good specimen
Face 1, coloured green CtalcJ.
Face 10, fibrous sample
Face 1, pure talc?
Face 1, good specimen
Face 3, coloured specimen
^
i 4
J&J-0060647
Code No. B1 B2 B3 B4 B5 B6 B7 B8 B9
TABLE 2
OTHER SPECIMENS EXAMINED
'Description Pure talc 1st face Greenish, talc 1st face
. Talc 6 inches above footwall Talc from above Inclusion Inclusion in talc Talc 2 ft above inclusion Section 2 ft above inclusion Pure talc 1st face Grey talc 1st face
Also examined
1) Batch, shipments of 00000 talc 2) Old samples of British, powders.
J&J-0060648
'OPTICAL EXAMINATION OF SPECIMENS II - 146
Thin and polished sections were -prepared of the specimens of wallrock and, where possible, the talc ore.
The minerals which formed a major constituent in at least one of the sections were quartz, muscovite, talc, chlorite, (var sheridanite), calcite, garnet, and tremolite; the latter only occurred as a major constituent in section 119.- Phases-- which were always minor or accessory were microcline, plagioclase, biotite, Pennine, epidote, clino2oisite, hornblende, actinolite (section 17), rutile, and opaque constituents pyrite, pyrrhotite. and chalcopyrite.
The identification of the minerals in the sections of these specimens was based on the optical characteristics of ' the minerals in transmitted and reflected light, both under plane polarised light (PPL] and crossed nicols (XN), combined with the results of the X-ray diffraction study of the crushed hand specimens. In some cases material was extracted from the sections and examined in R.I. liquids as in determining that the most common chlorite mineral in these specimens is a variety called sheridanite having a R.I. u equivalent of 1.590 0.005 and a birefringence of 0.012 - 0.014. Similarly much of the muscovite was nearly uniaxial with a R.I. of 1.600 correspond ing to the variety phengite, an abnormally siliceous muscovite. In the case of talc its confident determination optically is difficult since its optical properties are identical to musco vite. However, it was found that the common "feathery" form of the talc combined with the invariable occurrence of minute transparent inclusions (suspected to be silica) in the talc producing a 'dusty* appearance in thin section and a greenish colour in hand specimen, enabled talc to be distinguished from muscovite. Talc also exhibited slightly higher order inter ference colours in general. Where talc was only an accessory mineral to muscovite, as in some of the wallrock samples, then it could not be distinguished with certaintly.
In the following pages (no . 7 to 48 ) the Italian specimens are systematically described as regards their mineral composition and mode of intergrowth. Numerous photomicrographs taken under PPL and XN are provided with the description to mainly illustrate the rock textures which, it is hoped, will provide information useful in the comminution of particularly the talc ore samples, and also displays the non occurrence of asbestiform amphiboles in the talc ore.
J&J-0060649
Sp ecim en 'll
Specimen II consisted of several pieces of wallrock with, one piece displaying the talc/footwall contact. One polished section was made of the talc/footwall contact and one thin section of the wallrock alone.
The wallrock. is a schist which in thin section displayed a segregation of the main minerals into thin.lenticular bands composed, as in Figure 1, of long tabular aggregates of intermixed muscovite (var. phengite) and chlorite (var shericla-' " nite), and granular quartz exhibiting a polygonal grain boundary structure. Accessory rutile occurs as orientated inclusions in the chlorite and muscovite, and also opaque con stituents which in polished section were identified as dominantly pyrite metacrysts with minor pyrrhotite. Some subhedral porphyroblasts of plagiocla.se also occur.
Fig 1 . Photomicrograph, X 40, of thin section of wallrock II under crossed nicols. V schist of quartz (granular white-black}, muscovite (lamellar yellow-blue), and chlorite (lamellar white-blueish. greyl.
Specimen 13: 'coloured talc*
The minerals composing this specimen are major talc and
chlorite (var sheridanite) with the talc content much greater
than chlorite, together with accessory garnet, rutile, and an
unidentifiable finely dispersed phase occurring as minute
transparant inclusions along the cleavage planes and grain
boundaries of the talq and imparting a dusty brown appearance
to the talc in thin section and a greenish colour in hand
specimen. The talc occurs as medium grained feathery aggre
gates which are in places 'dusty* and grade into 'clean*
transparant aggregates which are free of any inclusions. It
appears that some retrograde metamorpaic process has caused
the inclusions to be removed or incorporated into the talc
Rt-rncfur K i n r o s i n n l p tAlrr r r v s t a l s
hot-h tvnps. The
J& J-0060650
8
minor chlorite is dispersed in the talc matrix as small lenticular and globular fibrous aggregates. Rare garnet, possibly a member of the ugrandite series because of its anisotropy, occurs as subhedral porphyroblasts.
H
i, .VI , A
Ia.*V
1
Fig. 2 . Photomicrograph, X 24, of thin section of 'coloured talc* specimen 13 under crossed nicols. Dominantly
talc (yellow-blue interference colours} showing murky brownishblack patches due to presence of fine unidentifiable inclusions.
Specimen 15: general ore A coarse aggregate of curving foliaceous and feathery
crystals of talc displaying evidence of shearing and translation twinning. As in specimen I3, dusty inclusions of a transpa rent mineral with, a general prismatic habit occurs dispersed in the talc. As before, but to a lesser extent, the talc is cleansed of these inclusions along zones associated with defor mation and translation twinning, and it appears that the inclusions have either been converted to talc (as in the con version of tremolite to talc by low temperature C O 2 metasomatism) or incorporated into the talc structure as a result of retro grade deformation metamorphism. Rare small subhedral garnet porphyroblasts also occur.
i
J&J-0060651
9
\ "' -v'r.
r-Kf-^r. .... .. .
"`H .
[
-: ? A:v*
. . .;V: ,';x ' '..;--or < "A
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, :>
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.
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Fig. 3. ,
Photomicrograph, x 24, of thin section of 'general ore* specimen I5 under crossed nicols showing the texture of the talc, and the 'murky' inclusion-rich talc compared to the clear inclusion-free talc.
Specimen I6
Specimen 16 consists of a very coarse aggregate of inter locking anhedral magnesite grains whichexhibit strongly irregular and angular penetrating grain boundaries. The mag nesite is characterised in thin section, Fig. 3a, by its marked change in relief and perfect rhombohedral cleavage in plane polarised light, and very high order interference colours, Fig. 3b, under crossed nicols.
Intergranular pockets of fine grained foliaceous and radiating prismatic crystals of talc together with race chlorite Cyar. sheridanitel occur. In places the prismatic clusters of talc appear to have formed at the expense of the magnesite, perhaps as a result of a retrograde thermal metamorphism with its formation being ascribed to a reaction between the magnesite and silica. One subhedral porphyronlast of plagioclase felspar occurs in the thin section.
J8.J-0060652
-/ - f t i - j p
ft ft)
V iV ftift :
j r* ft ft-rift-..
L - h i '. - .
-- I ' : '
,'
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... '/;.. .; ....'. '-.i- r
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ito'i/A.'t ..J^'3
Fig. 3a. photomicrograph., x 24, of thin section, of specimen Ig under plane polarised light, consisting dominantly of magnesite with minor talc and rare chlorite.
Fig. 3b
Photomicrograph of thin section of specimen Ig, mag x 24, under crossed nicols showing the occurr ence of small eauigranular and prismatic crystals of talc penetrating and interstitial to coarse anhedral magnesite.
J& J-0060653
XX
Sp ecim en I 7
This specimen of wallrock. is a quartz-muscovite-garnet schist (Figs. 4a, 4b, and 4c] containing some accessory actinolite, brown hornblende, talc and rare biotite.
The muscovite (var. phengite) forms long lenticular band3 showing a preferred orientation in a matrix of interlocked equigranular quartz grains displaying strongly irregular grain boundaries. Large euhedral porphyroblasts of garnet, forming one of the major phases, are dispersed throughout the rock.
Accessory subhedral tabular and rhombic sections of actinolite (colourless to bluish green pleochroism) occur, orientated parallel to the schistosity. The actinolite also occurs as rims to euhedral grains of rhombic and tabular outline which may have.originally been brown hornblende but now are pseudomorphed by what appears to be a mixture of talc, chlorite and residual hornblende. Some talc is present as small pockets within the muscovite layers but this identification is based on the form, the lower refractive index and the occurrence of dusty inclusions. The colour, birefringence etc. of the talc is otherwise the same as muscovite.
In polished section the main opaque accessory mineral is pyrrhotite occurring as subhedral laths lying parallel to the schistosity. Traces of chalcopyrite also occur, and some rutile rods mainly as inclusions in the garnet porphyroblasts.
i:r -
r
f i j..-. 1. '
No
?
Fig. 4a Photomicrograph of polished section of I7 showing ' ' ~~ pyrrhotite (white] , garnet (light grey], and muscovite-quartz (darker greyl. Very dark to black areas are pits in the surface.
J&J-0060654
12
Fig. 4b, Photomicrograph, mag. x 40, of thin section, of I7 consisting of garnet, muscovite and quartz under
. plane polarised light.
II
t
Fig. 4c.
Photomicrograph, mag. x 40, of thin section of I7 under crossed nicols showing sufcaedral garnet Cblack) , anfiedral interlocking cnartz (white-greyblack) , and lamellar muscovite (coloured).
J&J-0060655
S p e cim e n 18
In. hand specimen Is appears as a coarse aggregate of foliaceous talc varying in colour from white to greenish, white The general texture in thin section is of coarse foliated talc preferentially orientated and alternating with long lenses of a finer talc in which a preferred orientation appears to be absent as a result of shearing parallel to the schistosity. Minor chlorite Cvar. sheridanite) occurs as orientated laths intimately intergrown with the coarse talc.and as fibrous aggregates in the finer talc lenses. Rare anhedral garnet, possibly pyrope, occurs.
In thin section the talc which appears greenish in hand specimen is seen to be crowded with minute inclusions of a pinkish, mineral occurring as rounded to thin tabular grains and having a lower refractive index than the talc, A grey-brown amorphous material is also present. This material together with the granular inclusions is presumably responsible for the greenish colouration of' the talc in hand specimen. As in I3 and I5 the greenish talc has been cleansed of Inclusions along planes parallel to the schistosity by some later metasomatic process or retrograde metamorphic process. This 'absorbtion' of the inclu sions by the talc or removal of the inclusions, does not effect the form of aggregation of the talc crystals. Boundaries between, the clean transparent and 'murky' talc often transgress the schistosity and there is no change in the coarseness or mode of aggregation of the talc across such boundaries. X-ray diffrac tion of the transparent white talc and the translucent greenish talc revealed no differences and the composition of these inclusions is at the moment unknown. Figure 5, under crossed niois, shows such a transgressive boundary between the clear and. 'murky* or dusty talc.
--.'v*
h
tA
Fig. 5.
.t Photomicrograph, mag x 24, of thin section Ig showing the nature of` the talc intergrowth under crossed nicols, and the transgressive boundaries between.clear trans parent talc and tin? ineLim ion-rich 'murky1 tale which appears greenish white in hand specimen.
J&J-0060656
14
Sp ecim en I g t ' G re y t a l c 1 s t f a c e ' .
In specimen I9 talc and chlorite Cvar. sherldanite) are the main constituents. They occur intimately intergrown as long orientated foliaceous aggregates alternating with, finer platy aggregates in which the talc and chlorite fibres are randomly orientated and which form lenses elongated parallel to the. schistosity of the coarser foliaceous talc (Figs. 6a and 6b). Its in previous sections the talc appears murky in parts due to the presence of minute unidentifiable inclusions.
The talc is also crowded with small irregular and rod shaped grains of rutile . Rare subhedral porphyroblasts of garnet {possibly pyrope) also occur.
k t
I1-
i
ii i
Fig. 6a
Photomicrograph, x 40 mag, of thin section Ig under
plane polarised light showing subhedral garnet 3rains in an orientated foliaceous aggregate of talc and chlorite.
J&J-0060657
15
Fig. 5b, ^
Photomicrograph., x 40 mag. , of thin section Ig under crossed nicols showing garnet (.black) in a coarse matrix of foliaceous talc (bright interference colours) and chlorite (white to blue-grey interference colours).
K
J&J-0060658
16
Specim en' I m and I 7na * 'g r a n u la r t a l c '
Both. I]_q and I^OA consist of an intergrowth of medium grained and randomly orientated major talc with minor chlorite (var. sheridanite) (Fig. 7). Some small porphyroblasts of garnet also occur scattered in the talc/chlorite ground mass. In this specimen the talc is not crowded with inclusions as is the case in most of the other samples.
ivtV >> '7
7'.
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*VxJ v V r / i L '' - r .j - ~ - .t,
* wl--.-'* 7r.` X V'' ".*./V.c-->.* *
;
; iv>>.. 'k-U ej .
ySrM 'i ':i:,'w:- vit * ; wt. t:'.'**.
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. v y . .v -
;V. :
.'''*! L<*..;* ' '-.I "S <,
V->
-:vV*
.-i -
>? v r`-;>
-!
>* \ X'.'*'*-' ,,V- !- *
-x/ -X?
Fig. 7 .
Photomicrograph, x 40 mag., of thin section I10, under crossed nicols, consisting of talc (blue and yellow interference colours), chlorite (white and greys), and garnet (black).
Specimen Iii : 'carbonate and talc*
Specimen I n consists dominantly of a mosaic of coarse to fine grained anhedral interlocking magnesite grains with interstitial pockets of coarse to medium grained foliaceous aggregates 'of talc (Figs. 8a and 8b ) .. The talc is crowded with near sub-microscopic inclusions of a transparant phase together with a brown amorphous material which causes the talc to appear dusty or turbid in thin section. Some fibrous chlorite (var. sheridanite) occurs as small pockets intergrown with the talc. Traces of rutile and pyrite occur.
(
J&J-0060659
<vj
Fig,' 8a
Photomicrograph., x 24 mag., of thin section I]_]_ under plane polarised light showing a subhedral pyrite metacryst (Jblack.1 in a matrix of compact granular magnesite with interstitial foliaceous talc Ctop centre},,
'T .i;vr?Vv;'
Y- W : ;X;-v.
> ~ w v-> fc\*->
S i -: r ' i' xt
v f e v - X / ;Xv
\
t> '
j7
- ---viS;,f:>--t'
" \ X r>" *>
fri - 4 '?i'.; ' '' ':'X 3 > '
r
Vf. f=S ' - ; - ''. -.<v ^ v 4'
^h'.Mn.CQ t
..tesi-Vili a ( -JU--.WWW'
-. 1 ;;
Fig. 8b .
Photomicrograph, x 24 mag., of thin section I n under crossed nLcols showing a pyrite metacryst tblnirk.} In n <jr.malar mnqneti Lin matrix, wit h a
foliaceous interstitial aggregate of talc (top centre}, `
18 Sp ecim en 1 n
An aggregate of anhedral quartz as the main constituent with minor interstitial muscovite and green chlorite (var. __ pennine} Fig. 9. The long muscovite laths show-a-preferred * orientation. Chlorite occurs in interstitial pockets as randomly orientated platy grains. Some epidote is present and a trace of magnesite.
The chlorite displays a pleochroism from light green to brownish-cream, and anomalous blue interference colours in some cases. However, most of the chlorite grains display lower second order to upper first order interference colours. Thus a range of chlorite composition is probably represented in the section.
'4
Fig. 9* Photomicrograph, x 40 mag., of thin section 1^2 under crossed nicols.
Specimen It3 This specimen ^onsists of an aggregate of mainly medium
grained platy to fiorous chlorite (.var. sheridanite) and eqruigranuiar cuartz.1 These two enclose ragged replacement residuals of calcite and subhedral metacrysts of pyrite with rare- chalcoovrite.
J&J-0060661
19
V'tv-r*;
*
'v*y'\/. i V />'-4,t
**
*..f Jj*
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v^**\ry.1# X V
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i
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) : > V ;:>' V
`M N`-
-i
'.Vv*i-'!> >
Fig. 10a Photomicrography x 40 mag., of thin section
*13 under PPL showing subhedral pyrite metacrysts (black) in a matrix of dominantly chlorite and quartz with minor calcite.
'f-f* r' /---V * 'v
7M
' \ !
r-V, r v . - ^ O \ Xv-s. ....* J n-* ' - .>.:( - U.- .. V ,/ '- i !.' *> ,
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rr-u'iT>. ' . r - . Nf
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> y"
fr/'i h f f k V-,
".. A
: (:.v v<'-- N l/.V^-vr
vi?\ V \ r ; '
FIqV XOb
i
Photonticrograph, x 40 mag. , of thin section 113 under XM showing chlorite (fibrous white and greenish-grey) and calcito (coloured) enclosing subhedral gruLmi of pyrllt (black). Equigranular grey grains are quartz.
J&J-0060662
Sp ecim en 1 ^
This specimen is dominantly composed of very coarse grained magnesite enclosing minor amounts of talc and very minor chlorite"(var. sheridanite}. The talc and chlorite form pockets of radiating lamellar and foliaceous crystals uu in Pigs. 11a, Ufa.
pig. 11a
Photomicrograph, X 24 mag., of thin section I^4 under PPL of coarse magnesite and 'intergranular pockets of 'dusty' and 'clear* talc.
Fig. lib ....r,
Photomicrograph, x 24 mag., of thin section under XU of magnesite (greenish) and pockets of
radiating lamellar talc (blue, purple, yellow).
J&J-0060663
21
Specimen' It
**
This specimen of wallrock is a qarnet~muscovite-quartz schist with minor green chlorite, biotite, and rare talc and feldspar (Figs. 12a and 12b).
The garnet occurs as large (l-*3mm diam.) porphyroblasts altered along irregular fractures to a mixture of greenish chlorite, biotite, and some feldspar, and enclosed in a matrix composed- of orientated tabular grains of muscovite, forming elongated lenses, and alternating with 'mosaic' granular quartz containing randomly dispersed biotite and chlorite flakes.
V //>.>7,. I
"v v
. -Q '*
' v
. -V.?, -'*,> *
M/ M- i"-' -'. ; '
'J t.'A.r J. ' f
..< /: v '-Li - *
77v".v-' t . V' ;-- v' h i > VV.\ '
*.,, *k-V - : - '. '' '-S
v**,*
..\N V
**! V
>
Fig. 12a
Photomicrograph, x 24 mag., of thin section Iisa. UNDER PPL showing a large altered porphyroblast of garnet in a matrix or dominantly muscovite with minor quartz.
J&J-00606S4
22
'*"*'/ *
'
*v9>
^\v
*.***'ipra *. , /
*'.
*
ni
>.\ A
\'f .4
:v*.-vv
: n AP
V \ ] . .V
k k>. 'V P
KK* V- : , v j , -s v
i ..r.^?*'^' ....,>:':-.; -**'--*vof\Piin.<d:h^&.-
* -\*Ij%r.y t -:,V;
.. \
Fig 12b.
Photomicrograph., x 24-mag., of thin section ^lSA uflcter crossed nicols. Garnet (black). Muscovite (dominantly purple interference colours). Quartz (white and greys).
t
J&J-0060665
S p e c i m e n l i e;
This specimen is dominantly composed of chlorite (var. sheridanite) and quartz- as orientated aggregates producing a schistosity. Very minor amounts of magnesite and talc occur. The talc occurs as thin laths, intergrown with the chlorite (Fig. 13b).
Fig/ 13a
Photomicrograph, jc40 mag., of thin section 1x5 under PPL showing the irregular but preferred elongation of granular quartz segregations in a matrix of fibrous chlorite (var.'~sheridanite).>
Fig. 13b
Photomicrograph, x 40 mag., of thin section I15 under XN, composed of chlorite (fibrous white, greenish grey, black.), quart2 igranular white-grey-black) , and talc (blue, red, and yellow interference colours).
J&J-0060666
24 Sp ecim en I i a : ` f i r s t f a c e in c lu s io n '
This specimen is composed of a medium grained aggregate of dominantly chlorite (var. sheridanite) and quartz, with minor magnesite,' clinozoisifce/ talc, and muscovite, and displaying a poor schistosity. Scattered eunedral to subhedral pyrite metacrysts occur as well as medium grained crystal aggregates of rutile associated with clinozolsite forming 'stringers' parallel to the general schistosity of the rock.
In the photomicrograph of figure 14a the brownish speckled areas are dominantly chlorite although in Figure 14b talc and muscovite are more apparent because of their inter ference colours.
Figure 14a Photomicrograph, x 40 mag., of thin section ^ under PPL.
i
J&J-0060667
0
r
r" i 9 ' ''%V> -V A ~ ' ' "*:v'~'~-v to . 'r r -
:&; V.-: -
' >
*:*) >i
\A''^vi%vi-*M*
. - -a j
\ r * `r \ f) -f*>.- .A'
' v;*-
v ,v .
;yr'
/
>^ '`W"\
K : rV.V , ^
-. ^ -
-' '^ ,.;vi .*: *~
='/yv '^A.
aA X
i r '> -y >
;fV . .
-/
-V^ ,wr''a-
*.4 tr
*. a ;y
Tig.- 14b
Photomicrography x 40 mag. r of thin section Ij^g
under crossed nicols. A chlorite - quartz rock with minor talc and muscovite, and accessory magnesite, clinozoisite, rutile and pyrite.
J&J-0060668
S p e cim e n Z n : 1f o o t w a l l 1
This specimen of footwall rock Is a muscovite-auartzgarnet schist consisting of long lenticular anhedral quartz aggregates. Both are enclosing fractured and altered euhedral porphyroblasts oE garnet. Accessory sphene also occurs as well as serpentine-quartz pseudomorphs after a minerai dluplaylng rhombic and tabular suctions.
h'r>;/vNr4v
:-.v" - w > ..%-. :H*.'*>; ^
i^%v i : ; ' d ... '*if.
? /.!
Piq. 15a Photomicrograph, x 24 m a g . o f thin section 117 under PPL showing garnet euhedra in a matrix of segregated
quartz and muscovite.
I' ^fc"
i,F>',,'** f'^*0,0-'
' i.
O f s
' 'fete;::'
-:f% k
. '__A -V'
\\
VV ~J * }
-. .. . i ,
J
-- s-~. --
- ft* .. ,,
!
, .. V , i , " ->' -s
. s^v/ ; ^
h ^ s .u ,, j>;;
p.Tvi-v.; \}\v-. i 't
--o'-^
j -`-o \ --',,'-
p*
'.f^- p -4
Fia. 15b Photomicrograph, x 24 mag., of thin section. I17 under -- - XN. Garnet Cblack) quartz (.white to grey) , and
muscovite Cl^sllar and coloured) .
J&J-0060669
Sp ecim en 1 -^ ; ` F a c e 3 , c a r b o n a t e / t a lc *
A coarse to medium grained aggregate of subhedral inter locking grains of magnesite with, minor ta'lc occurring as scattered small interstitial clusters associated with rare chlorite (var. sheridanito) and muscovite (Figs. 16a, 16b).
Fig, 16a Photomicrograph, x 24 mag,, of thin section Ii8 under PPL of granular magnesite with., scattered tabular crystals and clusters of talc.
t: i - r t 9 - " . ' * ' fe y -rr.*: Pr.---?- -a '
^
* v '-J ;
-a *i
.... \
'y -.l\
t '
Fig. 16b
Photomlqrograph, x 24 mag,, of thin section Ii_g under XN of granular magnesite thigh order interference colours, 'and scattered tabular crystals and clusters of talc (top right, coloured) and rare chlorite
(white.to blue-grey colours).
J&J-0060670
apecuaen I t q :
This specimen consists of an aggregate of coarse grained anhedral magnesite intergrown with solitary bladed crystals and crystal aggregates of tremolite associated with minor amounts of fine fibrous talc and rare anhedral grains of quartz (Figs. 17a, 17b).
Fig. 17a Photomicrograph, x 24 mag., of thin section of under PPL, showing coarse bladed tremolite inter grown with, very coarse grained magnesite.
Fig. 17b Photomicrograph., x 24 mag. , of thin section I^g under crossed nicols showing coarse bladed tremolite and'anhedra'l coarse-grained magnesite with minor small fibrous aggregates of talc
. (top left}..
J&J-0060671
Specim en-
1I n c lu s io n , f a c e 2 * .
Specimen I21 is composed of a fine grained interlocking aggregate of anhedral magnesite, as the major constituent,
associated with, scattered laths and interstitial fine-grained
fibrous aggregates of very minor talc (Pigs. 18a and 18b).
Fig. 18a Photomicrograph, x 24 mag., of thin section I21 under PPL. Magnesite with rare talc.
If-;:
.!;> * - ./':'*-?.>* V ' .**\ i< *;?
*>
% iy
fr*i: ;
P>,,'>2 AV h>^.-->*i1 :?>_ J V - X -
Fig. 18b Photomicrograph., x 24 mag., of thin section I21 under crossed, nicols. Magnesite with rare talc.
J&J-0060672
30 Sp ecim en Z? 2
This specimen is dominantly composed of coarse subhedral to euhedral interlocking grains -of magnesite associated with intergranular fibrous clusters of talc which often enclose smaller euhedral magnesite grains (.Fig. 19). ...
j
Fig. 19 Photomicrograph, x 24 magnification# of thin section I22 under plane polarised light. Magnesite
^and interstitial aggregates of talc.
t 4
J&J-0060673
Sp ecim en l 2 3 t ` B la c k G n e is s 2* b elo w t a lc v e in '
Specimen I23 consists dominantly of medium grained anhedral
interlocking quartz as orientated bands enclosing large micro-
cline anhedra and anhedral aggregates. Scattered platy
aggregates of muscovite occur orientated parallel to the general
direction of the quartz banding. Minor epidoto and chlorite
also occur (Figs. 20a and 20b).
"
p i :
' " v
Ftq. 20a Photomicrograph, x 24 mag., of thin section I23 under PPL, Quartz-muscovite-microcline gneiss.
V
*:**& ly j y
-s^v. ' - ^ 3
pi*-V,, " .. ,i -'rt*1-. l. / `
* v- T ' 1.
*". Kt; J .r ,-
V* ': ^ . ...> ; '
1- ^-''S-r-i ->1*<*r*=# '* ->S1-- ....A r-IX..4
F i q . 20b P h o to m ic ro g ra p h , x 24 m a g ., o f t h in s e c t io n I 23 u n d er XN. Q u a rtz -m u s c o v ite -m ic ro c lin e g n e is s .
J&J-0060674
Sp ecim en I ? 4 ; ; rF a c a 2 , T a lc .n e x t to ca rb o n a te *
This specimen of talc ore consists dominantly of coarse
fibrous talc with minor chlorite Cvar. sheridanite) occurring
as small lenticular fibrous aggregates within the main mass of talc (Pigs. 21a and 21b). A few small subhedra of garnet are present. As in previpus specimens there are two forms of talc present; (1) a talc that in thin section appears brown (Fig.2la) under plane polarised light due to finely dispersed dusty inclu sions of a transparant mineral and a brown amorphous material, (2) a clear transparent talc free of inclusions which appearu to have' been formed at the expense of the other by some metuuomatlc 'cleansing* process. Talc crystals in optical continuity can bo
seen to change sharply from 'dusty* brown talc to Lho clear talc
Fig.21a Photomicrograph, x 24 mag., of thin section I24 under PPL. `Dusty* and clear talc enclosing small lenticular aggregates of chlorite. .
Fq.21b Photomicrograph, x24 mag., of thin section I24 under XN Coarse talc with lenticular aggregates of chlorite.
I
i
I i.;i it.
This specimen of footwall rock, consists of an. interlocking aggregate of medium grained anhsdral quartz enclosing occasional large anhedra of microcllne feldspar (Figs. 22a,22b). Minor
magnesite occurs as pockets interstitial to the quartz, and also scattered laths of muscovite. Green chlorite (ponnine)and epidote occur in trace amounts.
Piq. 22a Photomicrograph, x 24 mag./ of thin.section 125 under PPLj dominantly a quartz--microcllne rock. with, minor
muscovite and rare pennine and epidote.
IT-* > m ' . / ~
r , i. \
....
P ig . 22b
f-' * - V._____ I.
V
P h o to m iq ro g ra p h , x 24 m a g .,
XN.
-
o f th in
,r*rr*"~&
s e c tio n I 25
under
J&J-0060676
Sp ecim en 126
This specimen contains chlorite, talc, magnesite and rutile One part of the thin section consisted of a massive coarse fibrous and feathery aggregate of talc enclosing pockets of coarse magnesite. This texture graded into one which was dominantly fine grained chlorite {var. sheridanite) intimately intergrown with minor quantities of fibrous and platy talc (Fig. 23) as well as scattered small equigranular and rod-shaped rutile crystals.
i
9
Kx v
P ig ili >1
M i ki
i J i j'i.V m
Fig.;'23. Photomicrography x 40 mag., of thin section I2G under crossed nicols showing minor' talc (colqured) inti mately intergrown with major chlorite.
s
I
J&J-0060677
Sp ecim en 127
Specimen I27 is dominantly composed of quartz, chlorite (var, sheridanite) and talc (Figs. 24a and 24h). Thin lenticular bands of coarau feathery Laic and chlorite alturuatu with anhedral granular interlocking aggregates of quartz. Scattered inclusions of rutile and opldoto occur, uu wuil an occasional large mlcrocline anhedru.
Fig, 24a Photomicrograph., x 40 mag., of thin section I27 under
PPL, showing a fibrous and feathery aggregate of talc and chlorite enclosing anhedral segregations of quartz
V.S>i f ' y \ ' ^
' .v `.v . A'v
;'-v . 'if.r;: iW
'1
' . a
; f ' L
v :'-V i'l' .i-rV'\Y ,1
F ig . 24b P h o to m icro g ra p h , x 40 m a g ., o f t h in s e c t io n 127 under XN.
J&J-0060678
S p e c im e n I;>q
36
Specimen I29 is a gneissic rock consisting of segregated bands of medium to fine interlocking anhedral quartz grains alternating with minor muscovite as'orientated platy clusters and enclosing large microcline anhedra. Some rare Pennine and very rare epidote occur intergrown with the muscovite.
> ,. ,,'V >; ,, \ > i \
t `-/>c
'Va \ \ ' 1v i ' 1
Fig. 25a Photomicrograph, x 24 mag., of thin section I29 under PPL; quartz, muscovite, and microcline (top left)
* t> ' ' >.Vv
k- '
.
f.?'V V.-
i
.yi." . ... { Jr*)
V\-V "
-1
?- --iY '
,.k - > -t?v. ;
-v *
'/ i .*5`.t. - J '-.j
rA,-':
./ f
- r 'C r r Y !\ ' r .. w.- ty.v i>v; i 1 1
'1 ' /
V f.),-. 1 .
r v : y V . V
Fig* 25b Photomicrograph, x 24 mag., of thin section' I29 under - ---- XN*
J&J-0060679
Sp ecim en Ir n
37 .
Specimen I31 is a muscovite-quartz schist containing minor genuine/ sphene and tremolite.
The rock, is dominantly made up of coarse orientated lamella segregations of muscovite intergrown with flakou of minor greenish brown chlorite (pennino) arid enclosing uuhedzal to uublKulral grains of sphenc. Minor interlocking' fine to medium grained quartz segregations occur alternating with tho muscovite bunds. Hexagonal sections of an amphibola, probably treraolito, occur dispersed in the muscovite matrix.
/\ *'
^V. '
,;
;`V v \
v. >,
'-Vi*?.u
vy.'SVv
- A .-V
*. v; 1.J- <, !
S
A - : ' `V '-:,V V *
-V-;
A *.7/: v-. `V ' i *
A
#.
5. 'A-
. 'A**-'- .
Fid. 26a Photomicrograph, x 40 mag., of thin, section I31 under PPL; muscovite-quartz schist.
.. *.** , - . .-7;...
V'v J
\ '*. \ .* v ;
.V AAvVXA'AAi
. '< ' A 7'.? 'J
Fiq. 26b Photomicrograph, x 40 mag., of thin section I31 under XN; muscovite-quartz schist.
J&J-0060680
38
S p e c im e n i-^?
This specimen consists of coarse feathery lenticular aggregates of dominantly chlorite (var. sheridanifce) intimately intergrown with minor amounts of talc (Figs. 27a and 27b).
Small inclusions of rutile occur along the boundaries (shear planes) between the chlorite aggregates and also along chlorite cleavage planes. Finely dispersed submicroscopic dusty inclusions of an unidentified phase similar to that found in talc occur in the chlorite.
Fig. 27a Photomicrograph, x 24 mag., of thin section I32 under XN. Feathery aggregates of sheared chlorite (white to greenish, grey to black) with minor talc (coloured) .
Fig. 27b Photomicrograph, x 24 mag., of thin section I32 under XNo Finer grained chlorite-talc mixture.
J&J-0060681
Sp ecim en I n
' *
This specimen of talc ore consists of a medium to fine grained' randomly orientated intergrowth, of dominantly talc with, minor' chlorite (var. sheridanite). The chlorite is intimately mixed with, the talc (Fig. 28). Some pockets of coarse interlocking anhedral magnesite grains occur enclosed by the talc-chlorite matrix.
F i g . ,28 i
J&J-0060682
40
S p e c i m e n I35
This specimen consists dominantly of magnesite as a very coarse to medium grained interlocking aggregate of euhedral to subhedral grains. Minor tremolite- occurs as long prismatic crystals forming interstitial clusters, and as solitary crystals penetrating the magnesite and along the grain bound aries of the magnesite. Minor chlorite (var. sheridanite) and rare talc occur associated with the tremolite segregations. CFigs. 29a, 29b}.
Fig. 29a Photomicrograph, x 24 mag., of thin section I35 under PPL. Magnesite-tremolite-chlorite-talc rock.
r I-
'**r`,iryv
/ i>-'>V
.1 *...'. " t '"} .
\* 4
^
y / Vv-
v*>;/=:
>.A V . / V '
. . <1 ,
'1. - -
r .-' ;
S .' ^
~r <
A V
. :V .
.A a
tw. ai~~. Fig.'^9b Photomicrograph, x 24 mag., of thin section 13s under
XJJ. Prir.matic tremolite in magnesite in the extinction position.
J& J-0060683
Sp ecim en 1 37
This specimen consists dominantly of magnesite with minor talcp The magnesite occurs as an aggregate of very large magnesite anhedra enclosed by finer grained subhedral magnesite which is intergrown with feathery intergranular clusters of talc (Pig. 301.
t
.^
Fig. 30
Photomicrograph. of thin section 137, x 24 mag., under XN showing the finer intergranular magnesite associated with small laths of talc (fibrous and coloured).
J&J-0060684
42
S p e c im e n I-^q
This specimen is dominantly composed of talc forming coarse feathery aggregates intimately intergrown with minor finer grained chlorite (var. sheridanite) and containing fine disseminated inc lusions of rutile. Occasional fine grained quartz as well as larger oval-shaped augen of quartz and rare garnet occur scattered throughout the talc matrix. The talc is for the most part crowded with inclusions, as in previous sections, but elongate areas of `clean.1 talc occur as in Fig. 31a.
Fig. 31a Photomicrograph, x 24 mag., of thin section I39 under PPL
Fig. 31b Photomicrograph, x 24 mag., o thin section I39, under XN
J&J-0060685
Sp ecim en l a i
This specimen of talc ore consists of a coarse aggregate of feathery talc intimately intergrown with minor' chlorite (var. sheridanite), and enclosing rare large porphyrofalasts of subhedral garnet which, occasionally contain long prismatic inclusions of tremolite .(Fig. 32a)
o )
il I !i:' i i'
I
$
i Fig.-32a Photomicrograph, x 24 mag., of thin section I41
i . under XN. Feathery aggregate of talc with garnet
!
porphyrofalast (bottom right, black),
>
i
t
J&J-0060686
Sp ecim en I 4 2 : ' N o . l F a c e , g re e n c o lo u re d '
t\
Specimen I42 consists dominantly of an aggregate of fine grained fibrous chlorite (var. sheridanite) intimately Inter-grown with minor very fine grained talc as in Fig. 33.
Fig. 33
Photomicrograph, x 24 mag., of thin section I42 under crossed nicols of chlorite (white, greenish grey, black.) , and fine grained talc (yellow) .
J&J-0060687
45
S p ecim en 1 4 3- 'F a c e 10 f ib r o u s sam p le *
Specimen I43 consists dominantly of' chlorite (var. sheridanite), occurring in the form of a coarse sheared fibrous aggregate intimately intergrown with very minor talc as in Figure 34
Fig. 34
Photomicrograph, x 40 mag., of thin section X43 unde crossed nicols showing deformed fibrous chlorite (white-greenish grey-black) intergrown with platy and prismatic crystals of talc (coloured),,
Specimen I43A As for I43 the specimen consisted dominantly of chlorite
Cvar. sheridanite) with very minor talc. The `cross fibre' type texture found in I43 and produced by shearing at right angles to the schistosity was absent in specimen 143/^.
v
J&J-0060688
Sp ecim en I 4 4 ; ` F i r s t fa c e p u re t a l c "
A coarse aggregate of lamellar talc showing a preferred orientation and enclosing augen of what appears to be an intimate intergrowth, of quartz and serpentine (Fig. 35). Both talc crowded with, fine unidentified inclusions and `clear* talc are present. See also description, for I45.
*
9
Fig. 3 5 Photomicrograph., x 24 mag., of section X44 under crossed niois showing coarse lamellar'talc enclosing rare anhedral segregations of probable serpentine-quartz composition.
J&J-0060689
Sp ecim en I dm ' N o . l good sp e c im e n 1
This specimen of `talc ore1, consists nearly wholly of talc occurring in the form of a randomly orientated 'matted* aggregate of fibrous talc enclosing minor quartz-serpentine augen. As in previous sections the talc is rendered murky or dusty by fine inclusions of a brown amorphous material and ,an unidentified transparant phase. In places the talc has -been cleansed of these inclusions along zones which appear to be independent of any intergrowth or crystallographic features of the talc (Fig. 36).
k,-. >h.;J
h'v ~%e.>v'/ ,y>t\-, $.-f*'> ;*-V'?' y
y
Pig. 35
Photomicrograph, x 24 mag., of thin specimen I45 under crossed niois showing the form.of aggre gation of the talc and the difference between the murky* talc and the linear transgressive zone of
*clear*1talc.
J&J-0060690
5Eeciji]ien_X46$ *No03 face# coloured* This specimen consists of very coarse lenticular
aggregates of long fibrous and feathery talc crystals enclosing rare anhedral porphyroblasts of garnet.
J&J-0060691
49
DIGESTIVE TESTS To confirm the presence of acid soluble carbonate'material
and also to help identify the type of carbonate present in the rock specimens collected,each powder specimen was subjected to a digestive test.
Half gram quantities of each of the powders were treated with normal hydrochloric acid for several hours at approximately 70C. The residues were reweighed and the filtrates were analysed for their calcium and magnesium content using the EEL, 240 Atomic Absorption Spectrophotometer. The aim of the digestion was not to estimate the total acid soluble fraction only to help establish the carbonate minerals present and to estimate roughly their quantity to help interpret the X-ray powder photographs obtained from the samples.
The results are present under-three headings, namely 'Rock Types*, `Carbonate Specimens', and 'Talc Specimens*.
It can be seen that only small quantities of carbonate material are present in the talc specimen group, similarly in the rock specimens with the exception of the "marble specimen which is practically 100% calcite. The carbonate group of specimens appear to be mixtures of calcium and magnesium carbonate with a number of specimens being possible,dolomites.
J&J-0060692
Specimen No.
11 17 112 113 115 116 117 120 123 125 127 129 131 134
Specimen NO.
14 16 111 114 118 119 121 122 130 135 137
Specimen NO.
12 13 15 , 18 19 HO 124 126 128 132 133 136
ROCK TYPES
% Weight Loss
<0 .2% 3.0%
<0 .2% 4.2% 6 .0% 4.8% 6 .0%
11.2% 1.4%
22.4% 9.0% . 3.6% 9.6%
92.2%
% Calcium
<0 .2% <0 .2% <0 .2%
1 .0 % <0 .2%
2 .0% <0 .2% <0 .2% <0 .2% <0 .2% . <0 .2% . <0 .2% . <0 .2% >2 0 .0 %
% Magnesium .
<0 .2% <0 .2% <0 .2%
0.4% 0.4% 0.4% <0 .2% <0 .2% <0 .2% <0 .2% <0 .2% <0 .2% <0 .2% <0 .2%
CARBONATE SPECIMENS
% Weight Loss
22.8% 48.0% 2 1 .6% 44.2% 75.2% 37.8% 61.8% 91.2% 15.0% 50.8% 51.0%
% Calcium
3.0% 6 .0% . 3.0% 7.0% 14.0% 5.0% 8.4% 16.0% 1.9% 6 .6% 4.4%
% Magnesium
1 .1% 1.15% 6.4% 5.0% 24.0% 4.0% 8.0% 15.2% 1.5% 13.4% 24.0%
TALC SPECIMENS
% Weight Loss
3.6% 1 .6% 5.4% 6 .0% <0 .2% 4.2% 8.0 % . <0 .2% 12.6% , 1 .2% 5.6% 4.6%
% Calcium
% Magnesium .
<0 .2% <0 .2% <0 .2% <0 .2% <0 .2% <0 .2% <0 .2% <0 .2% <0 .2%
<0 .2% 0.34%
<0 .2%
0.4% <0 .2% <0 .2% <0 .2% <0 .2% <0 .2% <0 .2% <0 .2% <0 .2%
0.4% < 0 .2%
^ 0 #2%
/Continued....
J&J-0060693
51
TALC SPECIMENS (Continued)
Specimen No,
138 139 140 141 142 143 144 145
% Weight Loss
1 .0 % <0 .2%
7.0% . <0 .2%
0 .8% 6.2% <0 .2% 8 .0%
% Calcium
<0 .2% <0 .2% <0 .2% <0 .2% <0 .2% <0 .2% <0 .2% <0 .2%
% Magnesium
<0 .2% <0 .2% <0 .2 % <0 .2% <0 .2% <0 .2% <0 .2% .<0 .2%
i
J&J-0060694
r .. ii . ;( }'
I
Electron Microscope Examination of Italian
Mine Samples and Imported Batch Shipments of
Italian Powder
The main purpose of the electron microscope examination of mine samples and also representative fractions of the Italian powder has been to establish whether or not any particles corresponding to the commercial forms of asbestos were present. The electron microscope is an instrument which is most usefully employed in the examination of particles less than ten microns in size. It has been used in this investi gation therefore to examine only the finer particulate portion of the Italian samples. It may be argued that only a small fraction of each of the powdered samples was examined and that this was not representative of the total sample. However, we can assume that the fraction examined was representative of the dust formed from each sample and that it is this finer fraction which is the most important from a biological stand point. Also as the size of the biologically active commercial asbestos particles fall entirely within the particle size range examined we can consider the main aim of the examination to be entirely satisfied by only looking at the finer fractions from each, of the Italian samples.
To acquaint ourselves with the type of particles formed by the commercial asbestos minerals, Figs. A- have been included. They represent samples of Amosite, Crocidolite, Anthophyllite and Chrysotile asbestos. Also Figs. E-F have been inserted to demonstrate typical single particle electron diffraction patterns which can be obtained from the four asbestos types for comparison with patterns obtained from the Italian samples.
Sample Preparation
Small portions of the powdered rock samples and imported powder specimens were placed in 15cc centrifuge tubes to which distilled water was added. The powders were then dispersed first by hand shaking and then with the aid of a small ultra sonic bath. The concentration of suspended material in the tubes was adjusted by eye using dilutions of distilled water. The tubes containing suspended solids were then allowed to stand for 20 minutes to allow the larger particles of mineral to sediment to the bottom of the tubes.
Electron microscope grids coated with carbon films were prepared and small drops of the particulate material from each of the specimen tubes were mounted on specimen, grids and allowed to dry. The specimens were inserted into an A.E.I. E.M.6 . electron microscope and examined for particles resemb ling commercial asbestos fibres. Khere suitable particles were observed, selected area electron diffraction patterns were taken and compared with those produced by the commercial asbestos minerals. In all cases photomicrographs representative of the type of particles found in each sample were taken while interesting diffraction patterns were also recorded.
J&J-0060695
53
Particle Morphology
The carbonate rich materials were found to produce compact particles which were very electron dense. On the whole they were finer particles than those obtained after crushing talc rich specimens. No fibrous material whatsoever was found when carbonate material only was comminuted. The morphology of particles produced from the footwall rocks i.e. limestone, marble, gneiss and the amphibolites were also very compact, although in the gneiss specimen platey parti cles were present probably representing the muscovite content of the specimen. Again in the footwall rock specimens fibrous particles were very scarce. Those lath like parti cles detected resembled the amphibole minerals rather than chrysotile. Selected area diffraction patterns which were obtained from the lath like particles in no way resembled the typical amphibole fibre diffraction pattern. They were generally very distorted patterns containing streaks rather than spots indicating a rather stressed and deformed material.
The specimens which were composed of talc together with other mineral associations, presented a very different picture, as far as particle shape was concerned. In the main parti cles were flat and plate-like, some being very thin and translucent in the electron beam. Particle sizes varied from very small to quite large plates some with very sharp discrete edges, others with rather ragged outlines. Comparing parti cles from those samples of talc which varied in bulk morphology in hand specimens, no observable difference could be drawn between them. Similarly, a comparison of particles produced from talc specimens of varying colour revealed no differences in the overall particle shape. Similarly those specimens rich in chlorite did not form particles with any distinctive features.
There were, however, observable differences in particle morphology between individual powder specimens. In the main most produced good plate like particles, however, one or two specimens were found to contain considerable numbers of lath like particles, these being very thin in character. These particles resembled the amphibole asbestos type particle being less regular and also very much larger in projected diameter. Diffraction patterns from these particles matched those obtained from the platy particles with which they were asso ciated and in no way resembled the typical amphibole diffrac tion pattern obtained from single amphibole asbestos fibres.
Other fibrous particles were observed in the mainly talc specimens which to some extent resembled chrysotile asbestos fibres rather than amphibole minerals. They often had a somewhat textile appearance but were, however, crystalline. Diffraction patterns from these fibres were very distorted and in no way matched typical chrysotile or amphibole patterns.
J&J-0060696
The only group of specimens in which, amphibole fibres Here confirmed were in those specimens with known amphibole composition. However, even the fibres found in these speci mens barely resembled the fibres formed by the commercial amphibole asbestos minerals. To assess the particles produced from the pure amphibole mineral (Tremolite),found in three of the specimens, small crystals of the mineral were taken from the hand specimens and crushed separately. An examination of the-finer particles produced revealed stubby electron dense fibres associated with irregular lumps of the same mineral.. Diffraction patterns from these fibres were similar to those obtained from the commercial amphibole minerals, although they were more difficult to obtain because of the greater thickness of these particles. Other specimens in the group, which did not contain talc but were composed of sheet silicate minerals mainly muscovite, were also practically free of fibrous parti cles. There appeared to be no general tendency for these other minerals to form fine fibrous particles. A number of very fine short fibres were observed on grids prepared from several of the talc specimens, these were, however, chance small pieces torn from the edges of. talc plates. They appeared in those samples which had a tendency to form copiua numbers of very fine particles when subjected to comminution.
Tire specimens examined can be grouped into four categories on the basis of particle morphology and they are as follows:
(a) Talc specimens with impurities of carbonate and chlorite.
(b) Rock type specimens, i.e. footwall limestone etc.
(cl Those specimens composed mainly of carbonates.
CdJ Amphibole specimens with carbonate and talc.
The talc specimens were characterised by the large number of plate like particles often translucent in the electron beam. Rock specimens varied from specimens which were composed mainly of compact electron dense particles to those with some sheet silicate content in which plate like particles become apparent. Those specimens composed mainly of carbonate material produced compact rounded particles, often very small and grouped to gether in aggregates. Finally the specimens containing amphi bole were characterised by the compact nature of the particles with, evenly distributed fibres and very few translucent plates. The groups of particles described are illustrated by the foll owing micrographs which illustrate the various forms.
Selected area electron diffraction patterns obtained from single particles of the amphibole mineral are also presented showing the similarity of these patterns to those obtained from commercial asbestos fibres. Also included are single crystals patterns and polvcrystalline patterns, from talc, chlorite and muscovite rich specimens. It can be seen that they are very different in character to those obtained from the amphibole mineral. However, patterns from the sheet silicate minerals mentioned above are all very similar and it is impossible to identify each of these minerals from their
J&J-0060697
55 electron diffraction patterns or to tell them apart without applying a more sophisticated approach to the diffraction procedure. With specimen tilt facilities enabling the particle to be rotated through more than 45 discrimination is possible between certain of. these minerals.
As mentioned earlier, patterns obtained from lath like particles found in the talc specimens were identical to those observed from general plate like forms. Those fibres with a textile like appearance often only gave very streaked patterns but in one or two cases these also resembled very closely the normal talc pattern.
\
J&J-0060698
56 Examples of Commercial Amphibole' and Chrysotile asbestos particles together with, typical selected area electron diffraction patterns.
Chrysotile asbestos particles x 3000
Anthophylltto asbestos particles x 3000
J&J-0060699
Amosite asbestos particles x 3000
Crocidolite asbestos particles x 3000
J&J-0060700
58
Amphibole asbestos selected area electron diffraction pattern.
Chrysotle asbestos selected area electron diffraction pattern.
Jaj-0060701
Electron micrographs of particles produced from specimens which have heen classified as rock types.
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J&J-0060702
60
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Fig. 1.
Specimen I13 seam Inclusion showing passage into talc x 3000. The particles are mainly compact and electron dense. A few flakes, no fibres present.
Fig. 2.
i
Specimen I15. Talc footwall contact, x 3000. Compact particles with a few small flakes. No fibres present.
J&J-0060703
s*^
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Ftg. 3 . Specimen lie* Lithological inclusion from Face 1. x 3000. Compact electron dense particles. No fibres present.
t Specimen I17. Footwali rock sample, .x 3000. Mainly compact particles produced with a few plate like forms.
J&J-0060704
62
Fig. 5. Specimen 123* Black, gneiss, 2ft below talc seam, x 3000. Compact electron dense particles produced.
C7 O
o V_ * <4 ^ \1
^ f >
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Fig. 6 Specimen 125. Footwall limestone, x 3000. Compact electron dense particles.
J&J-0060705
63
a Specimen 127* Lithological inclusion face 1. x 3000. Flatey electron dense particles. No fibres.
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Fig. 8 . Specimen 129. Sample 6 Footwall. x 3000 Compact electron dense particles with, a few
Dlate-like forms.
J&J-0060706
64
Fig. 9
Specimen I31. Black inclusion.face 1. x 3000 A mixture of plate-like and compact forms mainly electron dense in character.
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m ^ p . . Specimen I34. Marble from tunnel wall, x 3000 Mainly compact electron dense particles with a few plate-like forms.
J&J-0060707
65
Electron micrographs of particles produced from those specimens mainly composed of carbonate minerals.
t
J&J-0060708
66
Fig 1 . Specimen 111 Carbonate inclusion with some * talc, x 3000. Particles consist of a mixture
of compact and plate-like forms.
t Pig. 2 . Specimen 1^4. Inclusion in talc seam Face 4 f
middle of seam, x 3000. Granular particles with plate-like types and lath-like forms.
J&J-0060709
67
Fig, 3. Specimen I^g. Carbonate/talc sample, x 3000. Particles compact and electron dense. A few plate-like forms.
i Fig. 4 . Specimen 121* Inclusion from Face 2. x 3000.
This specimen produced plate-like and compact particles with, some lath-like forma.
J&J-0060710
ye?7*
68
Fig. 5 Specimen 1 35. Massive carbonate from rear end of working, x 3000. Compact electron dense particles with, some plate-like talc particles.
l Fig. 6. Specimen I37. Carbonate in talc inclusion
x 3000. Compact particles together with some plate-like forms and rolled talc sheets
J&J-0060711
69
Electron. Micrographs of specimens of talc >cLth. carbonate and other mineral inclusions.
i
J&J-0060712
^r;i^v irM-.u-x-t .,,f
Ficr. 1 . Specimen 13. Coloured talc (Green) x 3000. Particles plate-like. Few fibres, rolled sheets and shords.
fig.-?.
Specimen I5. General ore, x 3000. Plate-like particles together with, short lath-like particles, also a typical example of textile type fibre.
J&J-0060713
Fig. 3 . Specimen 18 Massive talc, x 3000. Platelike particles with a few lath- forms also typical textile type long fibre.
Fig. 4. Specimen 19. Grey talc First Face, x 3000. Practic ally all plate-like with a few lath forms.
J&J-Q060714
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Fig:. 5 <> Specimen Ij q . Granular talc, x 3000. All plate-like particles.
Fig. 6.
Specimen 124- Talc next to carbonate inclusion, x 3000. This specimen v/as found to contain a large inumber of lath-like particles, as can be seen from the micrograph above. c diffraction pattern corresponding with an amphibole fibre was obtained from a selection of .the elongated particles.
J&J-0060715
Fig. 7 .
Specimen 126. Coloured talc inclusions, x 3000. The particles produced from the various coloured inclusions in the talc were found to be mainly plate-like with a few lath forms.
Fig. 8 .
Specimen 128* Talc/Quartz specimen, x 3000. Particles from this specimen were mainly plate' like but accompanied by more compact opaque particles. A few textile type fibres were observed.
J&J-0060716
74
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cy "ja "
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Fig. 9
Specimen 132* Face 2 inclusion from base of talc seam, x 3000. The specimen produced a mixture of irregular particles varying from compact to plate-like in form with, a few lath like particles.
Fig.10. Specimen I33. Talc from lower left end of working 3000. Particles mainly plate-like with some lath forms.
J&J-0060717
Fla. 11. Specimen 138 Pyrite/Talc specimen, x 3000. Plate-like particles with, some rolled tubes of talc.
i Fig 1 2 . Specimen I39. 5" ~ 0 coloured pieces from the
crusher, x 3000. These various coloured talc pieces produced only plate-like particles.
J&J-0060718
Flcu 13 Specimen 141* Face 2, good talc specii Plate-like particles together with roll sheets lath, forms and textile type fibi
Fla. 14 Specimen I42> Face 1, green coloured This cploured specimen produced platecles which were rather more electron de.
J&J-0060719
h1ft
Fig. 15. Specimen 143. Face 10. Fibrous looking hand specimen, x 3000. This sample was found to be practically all plate-like in form.
Fig. 16. Specimen I44. Face 1. Pure talc sample, x3000. Plate-like particles with some lath-like forms.
J&J-0060720
78
Fig.' 17.
Specimen 145. Face 1. Good talc specimen/ x 3000. A mixture of plate-like particles and fibrous forms, including rolled tubes and textile type fibres.
Fig. 18.
Specimen 145. Face 3. Coloured specimen x 3000. Plate-like particles with shards and lath, like forms, together with, a typical textile form, which can be seen to have a sheet-like form.
J&J-0060721
79
Electron Micrographs of particles produced from those specimens containing amphibole mineral and also from the amphibole mineral itself.
I
J&J-0060722
ou
Pig 1. Specimen I19. Tremolite/carbonate talc sample x 3000. Compact partides, a few lath, forms present.
Fiq. 2 . Specimen 120. Amphibole sample from Guiana level 1212. x 3000. Compact particles with numerous lath forms.
J&J-0060723
Figs. 3 and 4
Particles produced from single crystals of tremolite extracted, from specimens Il9 and 120* x 3000. Very few fibrous particles were produced when this specimen was crushed. Those that were fibrous in nature were thick and stubby in character, less than 5o% of the particles were elongated in shape.
J&J-0060724
82
Figs. 5 and 6 ' Selected area electron diffraction patterns obtained from amphibole particles found In specimens 19 and 120
J&J-0060725
83
Fig 7 - Typical selected area diffraction pattern obtained from talc plates*
I Selected area diffraction pattern obtained from a typical textile type fibre showing features of a rotated or coiled structure.
J&J-0060726
84
X-RAY ANALYSIS OF ITALIAN MINE SAMPLES
Introduction
This report concerns the X-ray powder analysis of the Italian mine samples. The samples were classified into three categories according to their chemical and physical properties:
til Rock* Type (ii) `Talc1 Type (iiil 'Carbonate* Type
All the samples were prepared by similar means and the procedure for obtaining the X-ray powder patterns was standardised.
Prom these powder photographs, several were chosen which clearly showed distinct mineral phases. These were used as standards for this group of samples. These standard patterns were compared against the ASTM index and this comparison illustrates the need to prepare standards for a particular locality from specimens at that locality.
The samples were compared with these standards by com puter methods and visually and the results and discrepancies between the methods of comparison noted,
LIST OF SAMPLES
See Table 1
SAMPLE PREPARATION
The samples were received mainly as large rocks and were labelled according to their appearance and location in the mire.
With the larger samples a section was cut from the middle to be a representative sample, for the smaller samples as many pieces as possible were crushed to form the represen tative sample.
These samples were then roughly broken up and placed in a *Tema* disc mill and ground for 5 mins, until all the sample was below approx. 100 mesh. These powders were stored in clean plastic bags. The samples, when required for X-ray analysis, were further ground (to less than 300 mesh) in a small agate ball mill and then sieved through a 350 mesh screen and stored in plastic bags.
The grinding mills and other apparatus used were thorough ly cleaned between samples and during the grinding care was taken to obtain a good representative sample.
J&J-0060727
All the samples were analysed using a Debye-Scherrer camera mounted on a Raymax RX 3-D X-ray generator, A copper X-ray tube was used with, nickel filters (0.02 mm thicki and the power rating of the tube set at 36 kV and 22mA.
The apparatus was carefully aligned and checked before mounting a sample. All the samples had the same exposure time of 8 hrs.
The samples were loaded into 0.5 mm diameter Lindemann glass tubes to be mounted in the Debye-Scherrer cameras. In the cameras Ilford Industrial 'G1 X-ray film was used. The film was processed using Kodak DX-80 developer and Ilford Hypain fixeri The films were developed for 5 minutes using a 1:4 dilution for the developer and fixed for 2 minutes. The films were then washed in running water for 30 minutes and allowed to dry naturally. The X-ray films were then measured.
Using an illuminated screen and .the line-spacings calculated, taking into account film shrinkage, from these line spacings the bragg angle and *d* spacings can be calcu lated.
STANDARD PATTERNS
When all the samples X-ray photographs had been measured and the *d* spacings calculated, they were visually inspected to find the film showing samples with pure mineral phases. These patterns were then taken as standards.
The samples were then broken up and the different mineral phases were sorted by hand to attempt to find a purer standard. These samples were then crushed in a similar way to the samples crushed beforehand. For X-ray analysis they were placed in 0.2 mm diameter tubes and given a 12 hr exposure. This method was used to give finer lines on the X-ray photograph and the larger exposure was to try and detect as many impurities as possible.
The 'd* spacings of the standards were compared with the A.S.T.M. index and also with themselves. They were compared with themselves to check that ail the Talc and Chlorite standards matched each other and were similar in intensity.
Several standards were prepared containing the same mineral. This was because the *d* spacings of the mineral varied slightly from sample to sample and especially with chlorite, depending on its composition the major reflections varied between 13.5% and 15.0%. This was mainly due to varying iron corftent and this can easily be seen on the X-ray films as it causes fluorescence with copper radiation and blackens the X-ray film generally.
J&J-0060728
86
RESULTS
For the analysis of the results the samples have been divided into five sections: (i) standard patterns (iil sample patterns Crock type! (ill) sample patterns (carbonate typel Civ) sample patterns Ctalc type) tv) batch sample patterns (includes old powders and
shipments). Two methods were used to find the mineral present in the sample. One method uses a computer program to detect the mineral. In this method the bragg angles of samples were compared with the bragg angles of the standard and the number of lines . fitted printed out. A print out was also obtained of all the standards which fitted a particular line to find all the possible minerals present and to see which lines were common to several standards. As this procedure is quite long, the lines in the sample Were first sorted into order of decreasing intensity and then the three most intense lines of the sample compared with the standards. If all three lines failed to match it was consid ered that that standard was not present and so the program deleted that standard from the comparison. At the end of the program the list of the standards was printed with the percentage of lines fitted to the sample noted. The obvious disadvantage of this comparison was that the program could take no account of the relative intensities of the lines and so a visual method was used to find which was the major mineral phase. The computer program usually found the mineral phases present in the samples but could not place them in the correct order
J&J-0060729
87
Patterns used as standards from the Italian mine samples and their comparison with A.S.T.M. data and against themselves.
J&J-0060730
-- JT
- Comparison against A.S.T.M.- index: 1 line unmatched, 1,1145 1
Patterns not included: 6-263 Muscovite -2M1, 7-25
Muscovite (1M), 7-32 Muscovite (2M1), 7-76 Ripidolite {.Chlorite}, 7-78 Thuringite {Chlorite} , 7-166 Bavalite {Chlorite}, 10-183 Peninnite Chlorite , 11-78 Dolomite, B and T Quartz..
Most probable minerals present: Talc Muscovite Calcite
Comparison against Italian Standards
Patterns not included; Chlorite (142), Chlorite (14), Muscovite (135), Magnesite (16), Tremolite (119/120), Dolomit
.Most probable Minerals present Talc
Visual comparison Talc, Calcite
Minerals detected ^ Talc, Calcite
` SAMPLE SIP 2 TALC
\ ;i
\ *
*cv?. ifi*rli.I
;.?1 -, .;* -
rt
-ir-
-.m - v ff f /"
Comparison aaainat A.S.T.M. index; 2 lines unmatched, 1.1159.
1.13538
'
Patterns not included: 7-76 Ripodolite (Chlorite), 7-78,Thuringite (Chlorite), 7-166 Bavalite (Chlorite).
Most probable minerals present: Talc, Muscovite, Calcite
Comparison against Italian Standards
Patterns not included: Chlorite (142), Chlorite (14), ' Tremolite (119/120).
Most probable minerals present: Talc, Muscovite, Magnesite.
Visual Comparison Talc, Chlorite, Magnesite
Minerals Detected Talc, Chlorite'/""Magnestie
J&J-0060731
iI
i i-
\ ' j; I
.I ii
i
I l\ ,C
' 5 1. tti \ I
ii I.
SAMPLE S IP 3 C H LO R ITE
Comparison against A.S.T.M. Index: 2 lines unmatched, 1.1739$. .o 1.29A
Patterns not included; 6-263 Muscovite -2M1, 7-25 Muscovite (IM) 7-32 Muscovite (2M1), 7-79 Forsterite (Olivine), 8-479 Magnesite
Most probable minerals present: Chlorite, Talc
Comparison against Italian Standards Patterns not Included: Muscovite (135), Tremolite (119 and 120)
Most probable minerals present; Chlorite, Talc.
Visual Comparison Chlorite. Talc
-Minerals Present . Chlorite.* Talc
SAMPLE SIP 4 CHLORITE
Comparison against A.S.T.M. index? 3 lines unmatched 1.1741A, 1.1318$, 1.0984$.
Patterns not included: 6-263 Muscovite -2M1, 7-32 Muscovite (2M1), 8-479 Magnesite, 11-78 Dolomite, 13-437 Boric Acid.
Most probable minerals present: Chlorite, Talc
Comparison against Italian Standards
Patterns not included: Calcite (134), Magnesite (137), Muscovite (135), Tremolite (119/120), Dolomite.
Most probable mineral present: Chlorite, Talc
Visual Comparison 1
Chlorite, Talc
'.
Minerals Present Chlorite, Talc
J&J-0060732
SAMPLE S IP 5 TALC
Comparison against A.S.T.M. Indext
Patterns not included: 5-586 Calcite, 7-25 Muscovite (1M), 7-77 Sheriaanite (Chlorite), 7-79 Forsterite (Olivine), 7-166 Bavalite (Chlorite).
Most probable minerals present? .Talc, Muscovite, Chlorite
Comparison against Italian Standards
Patterns not included: Chlorite (142), Chlorite (14), Magnesite(16), Tremolite (119/120).
Most probable minerals present: Talc
Visual comparison Talc, Chlorite
Minerals Present Talc, Chlorite
SAMPLE SIP 6 MUSCOVITE
O Comparison against A.S.T.M. index: 3 lines unmatched, 1.7999A,
1 3721A, 1.2741A.
Patterns not Included: 3-881 Talc, 7-79 Forsterite (Olivine), 7- 166 Bavalite (Chlorite), 7-183 Penninite (CHlorite), 8- 479 Magnesite, 11-78 Dolomite, 19-770 Talc.
Most probable minerals present: Muscovite, Chlorite
Comparison against Italian Standards
Patterns not included; Magnesite (137), Tremolite (119 and 120) . Dolomite
Most probable minerals present: 1
Visual Comparison
Muscovite, Calcite
Muscovite, Talc
Mineral Present Muscovite, Calcite
J&J-0060733
SAM PLE S IP 7 M AGN ESITE
Comparison against A.S.T.M. Index
Patterns not included: 5-586 Calcite, 6-263 Muscovite -2M1, 7-25 Muscovite (IH), 7-32 Muscovite (2M1), 7-160 Chlorite (Kotshubeite), 7-76 Ripodolite (Chlorite), 7-78 Thuringite (Chlorite), 7-166 Bavalite (Chlorite), 10-183 Penninite Chlorite, 13-437 Tremolite.
% Most probable minerals present; Magnesite, Dolomite, Talc
'Comparison, against Italian Standards
Patterns not included! Calcite (134), Chlorite (14) Muscovite (135), Tremolite (119/120),
Most probable minerals present; Magnesite, Dolomite, Talc
Visual Comparison Magnesite, Talc
Minerals Present Talc, Magnesite.
SAMPLE SIP 8 TREMOLITE
Patterns not Included; 6-263 Muscovite -2M1, 7-25 Muscovite (IM) , 7-32 Muscovite (2Ml), 7-42 Muscovite (3T), 7-79 Porsterite (Olivine).
Most probable minerals present: Tremolite, Talc, Calcite
Comparison against Italian Standards
Patterns not included: Magnesite (137), Chlorite (14), Muscovite (135).
Most probable minerals present: Tremolite, Talc, Calcite
Visual Comparison' Tremolite, Talc
Minerals Present Tremolite, Talc
J&J-0060734
jif 'i DOLOMITE
Patterns not included*. 3-881 Talc, 6-263 Muscovite -2M1, 7-25 Muscovite (IM) , 7-32 Muscovite (2M1), 19-814 Muscovite 2M1 CVanadian), 7-160 Chlorite (Kotschubeite), 7-79 Forsterite COlivine}, 13-437 Tremolite, 19-770 Talc.
Most probable minerals present; Dolomite, Muscovite
Comparison against Italian. Standards
Patterns not included: Magnesite (137), Chlorite (14) Tremolite (119/120).
Most probable minerals present: Dolomite, Talc
Visual Comparison Dolomite, Muscovite, Calcite
Minerals Present Dolomite, Muscovite, Calcit
SAMPLE SIP 10 CALCITB
Patterns not included; 7-160 Chlorite (Kotschubeite), 7-79 Forsterite. (Olivine), 13-437 Tremolite.
Most probable minerls present; Calcite, Muscovite
Comparison against Italian Standards .Patterns not included: Magnesite (16), Tremolite (119-120)0
Most probable minerals present; Calcite, Muscovite
Visual Comparison
Calcite
t
Minerals .Present .' Calcite, Muscovite
J&J-0060735
93 SAMPLE SIP II MAGNESITE
o Comparison against A.S.T.M. Index: I unmatched line 1.1085A
.Patterns not included; 5-586 Calcite, 7-25 Muscovite (IM) , 7-160 Chlorite (Kotschubeite), 7-76 Ripidolite (.Chlorite) , 7-78 Thuringite (Chlorite) , 7-166 Bavalite (Chlorite), 10-183 Penninite Chlorite, B & T Quartz.
Most probable minerals present; Magnesite, Dolomite, Talc
.Comparison against the Italian Standards
Patterns not included: Calcite (134), Chlorite (14), Muscovite (1351.
Most probable minerals present; Magnesite, Dolomite, Talc
Visual Comparison Magnesite, Dolomite, Talc
Minerals Present Magnesite, Talc, Dolomite
> v
J&J-0060736
94
Examples of Patterns Obtained from Rock. Type Specimens and Their Major Mineral Content from X-Ray Comparison.
t
J&J-0060737
;! >i
i
.t i
l
;i
i
i !>ft :>
I
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iI
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ii i ..i l
SAMPLE XI TALC FROM I'OOTt'RLL' CONTACT Comparison Patterns not Included: Magnesite (137), Tremolite (119/120). Most probable minerals present; Chlorite,. Muscovite, Talc,
Dolomite. Visual Comparison: Talc Chlorite, Calcite Minerals Present: Talc Chlorite, Calcite.
SAMPLE 17 MICA SCHIST Comparison Patterns not included: Magnesite (137), Talc (146),
Tremolite (119/120). Most probable minerals present: Muscovite, Talc, Quartz Visual Comparison; Muscovite, Talc,Quartz Minerals Present:
SAMPLE 112 FOQTWALL SAMPLE? AMPHIBOLITE O oo
Comparison; 3 lines unmatched. 6.4653A 1.2819A 1.225A. Patterns not included: Calcite (134), Magnesite (137),
Talc (146), Talc (IS), Tremolite (119/120). Most probable minerals present: Muscovite, Dolomite, Quartz. Visual Comparison: Muscovite, Chlorite, Quartz Minerals Present:
J&J-0060738
SAMPLE 113 INCISION SHOWING PASSAGE INTO TALC BOTTOM TRANSIT
Patterns not Included; Magnesite (137), Muscovite (135), Tremolite {119/120}, Dolomite
Most probable minerals present: Chlorite, Talc, Quartz
Visual Comparison: Chlorite, Muscovite, Quartz
Minerals Present: Chlorite, Muscovite, quartz
SAMPLE 115 TALC-FOOTWALL CONTACT
Bnwjwy imp*
cUi S
Comparison; Patterns not included: Magnesite (137), Tremolite (119/120). Most probable minerals present; Chlorite, Talc, Muscovite,
Quartz. Visual Comparison: Chlorite, Talc, Quartz Minerals Present; Chlorite, Talc, Quartz
?
J& J-0060739
97
SAMPLE 116 FACE 1 INCLUSION BELOW SEAM Comparison Patterns not included t Talc {.145) , Tremolite (119/1201
Dolomite Most probable minerals present; Muscovite, Chlorite,
Calcite, Quartz Visual Comparison: Chlorite, Muscovite, Calcite, Quartz Minerals Present? Chlorite, Muscovite, Calcite, Quartz
SAMPLE 117 FOOTWALL ROCK SAMPLE
Comparisoni 2 unmatched lines 6.6957A, 1.6305A Patterns not Included: Talc (146), Chlorite (142), Muscovite (135), Magnesite (16), Tremolite (119/120), Dolomite.
Most probable minerals present; Calcite, Talc, Quartz Visual Comparison: Calcite, Talc, Quartz Minerals Present; Calcite, Talc, Quartz .
i *. .
*
\
J&J-0060740
SAMPLE 120 AMPHIBOLE SAMPLE FROH GUIANA LEVEL 1212
Comparison: 1 unmatched line
o 1.6309A
Patterns not included: Chlorite (142), Chlorite (14), Muscovite (135), Magnesite (16), Dolomite.
Most probable minerals present: Talc, Tremolite, Calcite, Magnesite.
Visual Comparison: Talc, Tremolite, Chlorite
Minerals Present: Talc, Chlorite, Tremolite
SAMPLE 123 BLACK GNEISS
Patterns not included: Calcite (134), Tremolite (119/120) Most probable minerals present: Muscovite, Talc, Magnesite,
Quartz Visual Comparison: Muscovite, Magnesite, Quartz Minerals Present: Muscovite, Magnesite, Quartz
i K
J&J-0060741
99
SAMPLE X25 LIMESTONE FOOTWM.L
Comparison Patterns not included: Calcite (134), Tremolite (119/120) Most probable minerals present; Talc, Chlorite, Quartz Visual Comparison; Talc, Magnesite, Quartz Minerals Present: Talc, Magnesite, Quartz .
SAMPLE X27 LITHOLOGICAL INCLUSION
Comparison Patterns not included: Chlorite (142), Chlorite (14),
Tremolite (119/120), Magnesite (16), Dolomite Most probable minerals present? Talc, Calcite, Quartz Visual Comparison; Talc, Calcite, Quartz Minerals Present: Talc, Calcite, Quartz
SAMPLE 129 SAMPLE 6 FOOTMALL Comparison; 2 unmatched lines
oo 1.1526A, 6.3031A
Patterns not included: Calcite (134), Magnesite (137), Chlorite (14), Talc (15).
Most probable minerals present: Muscovite, Quartz, Dolomite, Talc
Visual Comparison; Muscovite, Quartz
Minerals Present; Muscovite, Quartz
J&J-0060742
SAMPLE 131 BLACK INCLUSION
Comparison; I unmatched line 1.2145A Patterns not Included: Magnesite (137), Talc :(I5),Dolomite `Most' probable minerals present: ' Muscovite, Calcite, Talc 'Visual Comparison: Muscovite, Calcite 'Minerals Present: Muscovite, Calcite *SAMPLE 134 TUNNEL WALL - MARBLE
Comparison Patterns not included: Tremolite (119/120), Magnesite (16) Most probable minerals present: Calcite, Muscovite, TalcVisual Comparison, Calcite Minerals Present Calcite
J&J-0060743
101
Examples of Patterns Obtained from the Carbonate Specimens and their Major Mineral Compo sition Obtained from Comparison with Standards.
J&J-0060744
102
SAMPLE 14 FACE 10 AMPHIBOLE
O oo Comparison: 3 unmatched lines 1.2586A, 1.0823A, 1.074A ' Patterns not included; Chlorite (142), Chlorite (14)
Dolomite Most probable minerals present: Tremolite. Talc, Magnesite V:t-sua3- Comparison: Talc, Tremolite, Magnesite ; Minerals Present: Talc, Tremolite, Magnesite
SAMPLE 16 QUARTZ Comparison Patterns not included: Calcite (134), Chlorite (14)
Tremolite (119/120) Most probable minerals present: Magnesite, Dolomite,
Talc Visual Comparison: MAGNESITE, Talc Minerals Present; Magnesite, Talc
J&J-0060745
103
SAMPLE 111 CARBONATE - TALC INCLUSION f?
Comparison: 1 unmatched line
III.
|j j /i j
'j /il-51 ;fw !)!. \
i r.frf
4
4 t i l i t <M* -
1.2143A
Patterns not included; Chlorite (142), Chlorite (14)
Most probable minerals present; Magnesite, Dolomite, Talc
Visual Comparison: Talc, Magnesite, Calcite
Minerals Present: Talc, Magnesite, Calcite
SAMPLE 114 SEAM 4 INCLUSION IN TALC
Comparison Patterns not Included: Magnesite (137), Chlorite (14),
Muscovite (135), Tremolite(119/120) Most probable minerals present: Dolomite, Talc Visual Comparison: Talc, Dolomite Minerals Present! Talc, Dolomite
SAMPLE 118 FACE 3 MAGNESITE AND TALC
Comparison: Patterns not included: Talc (15),. Tremolite (119/120) Most probable minerals present: Dolomite, Magnesite,
Chlorite Visual Comparison: Dolomite, Talc Chlorite Minerals Present: Dolomite, Talc, Chlorite,
t
J& J-0060746
104 SAMPLE I 19 IMPURITY IN TALC AND QUARTZ
Comparison; Patterns not included; Magnesite (137)
Most probable minerals present; Trempiite. Dolomite, Muscovite, Talc
Visual Comparison: Talc, Tremolite, Magnesite, Minerals Present: Talc, Tremolite, Magnesite
' SAMPLE 121 FACE 2 OCCLUSION (MAGNESITE)
" ' '" " " Y- - ' ? r ~ ...................
~
:
;/
* F- . - i-
1' . ?." j(:
J \ - *
. ). ; . : . .
f
. i
t i)
K -H - V k : V.- *V .
y . v . . . . i k;.
:>v> .
.
- T , ~ " . -----;\y v ; V
j ! ' : l \ l ' -r
i jj
;/ ; ; > -
C
/ h S. K * A : i
Comparison;
Patterns not included; Calcite (134), Chlorite (14), Muscovite (135), Tremlite (119/120)
Most probable minerals present: Dolomite, Magnesite, Talc
Visual Comparison:( Talc, Magnesite, Dolomite
V
Minerals Present: Talc, Magnesite, Dolomite
J&J-0060747
105
SAMPLE 122 MAGNESITE, DOLOMITE, TALC
Comparison; Patterns not included; Calcite (134), Talc (145), Talc (146)
Muscovite (135), Treraolite (119/120). Most probable minerals present; Dolomite, Magnesite,
Chlorite, Talc Visual Comparison: Talc, Dolomite, Minerals Present: Talc, Dolomite
SAMPLE 130 TALC AND OTHERS
Comparison; Patterns not Included: Magnesite (137), Talc (15),
' Treraolite (119/120). Most probable minerals present: Dolomite, Chlorite,
Muscovite, Talc. Visual Comparison: Talc, Chlorite
t Minerals Present:' Talc, Chlorite
J&J-0060748
106 SAMPLE 135 MASSIVE CARBONATE. END OF WORKING
Comparison: 'Patterns not included: Tremolite (119/120)
Most probable minerals present: Muscovite, Magnesite Chlorite
Visual Comparison: Magnesite Talc Chlorite Minerals Present: Magnesite Talc Chlorite
SAMPLE 137__CARBONATE AND TALC
Comparison Patterns not Included: Calcite (134) Chlorite (14)
Muscovite (135). Most probable minerals present: Magnesite Dolomite Talc Visual Comparison; Magnesite, Talc Mine.? -'Is Present: 1 Magnesite, Talc
J&J-0060749
107
Examples of Patterns and Major Mineral Content of Those Specimens Classified as Talc Types Obtained by Comparison.
J&J-0060750
108
0
SAMPLE 12 SORTING PIECES
Comparison Patterns not Included: Tremolite (119/120). Most probable minerals present; Chlorite, Magnesite, Talc Visual Comparison; Chlorite. Talc Minerals Present? Chlorite, Talc
t
SAMPLE 13 COLOURED TALC
Comparison;
Patterns not included: Chlorite (142), Chlorite (14), Muscovite (135), Magnesite (16), Tremolite (119/120), Dolomite,
Most probable minerals present; Talc
Visual Comparison;!
I Minerals present;
Talc Talc
J&J-0060751
109 SAMPLE 15 GENERAL ORE
Comparison: 2 unmatched lines
oo 18.1157A 7.0073A
Patterns not included: Chlorite (142), Chlorite (14), Muscovite (135), Dolomite.
Most probable minerals present: Talc, Magnesite
Visual Comparison: Talc Minerals present: Talc
SAMPLE 18 MASSIVE TALC
/ri.rrr
f t-
Comparison
.4 -
Patterns not Included: Magnesite (16), Tremolite (119/120).
Most probable minerals present: Talc, Chlorite
Visual Comparison: i
Minerals Present: ,
.Talc, Chlorite Talc, Chlorite
J&J-0060752
110
SAMPLE 15 FACE 1 GREY TALC
Patterns not Included: Calcite (.134), Magnesite (137), Muscovite (135) , Magnesite (16) , Tremolite (119/120),.
Most probable minerals present: Talc,, Chlorite
Visible Comparison: Talc, Chlorite
Minerals Present;
Talc, Chlorite
SAMPLE IIP GRANULAR TALC
Comparison
Patterns not included: Calcite (134), Magnesite (137), Chlorite (142) Chlorite (14) , Muscovite (135), Magnesite (16) Tremolite (119/120)
Most probable minerals presentt Talc, Dolomite
Visible Comparisont Talc, Dolomite
Minerals Present:
TalC/ Dolomite
i 4
J& J-0060753
Ill SAMPLE 124 TALC FACE 2
Comparison:
Patterns not included: Muscovite (135), Tremolite (119/120) Magnesite (16).
Most probable minerals present; Talc, Chlorite, Dolomite, Magnesite
Visual Comparison:
Dolomite, Magnesite, Talc
Minerals Present:
Dolomite, Magnesite Talc
SAMPLE 126 TALC INCLUSIONS
Comparison
Patterns not included: Calcite (134), Tremolite (119/120)
Most probable minerals present: Talc, Chlorite, Dolomite
Visual Comparison:
Talc, Chlorite
Minerals Present: '
Talc, Chlorite
J&J-0060754
112 SAMPLE 128 QUARTZ TALC
Comparison Patterns nob included: Muscovite (135), Tremolite (119/120)
Magnesite (16), Dolomite Most probable minerals present: Chlorite Talc# Quartz
Visual Comparisont Chlorite TaLc,Quartz Minerals Present: Chlorite, Talc, Quartz
SAMPLE 132 OCCLUSION FACE 2
i. i - -p.
mm
I q y ' h i t " 11
* **
Comparison
v > 'V
I; '
< ! ; :// ,:!s: .
-' W : '; `
' U f
!}; ;
v
i..- - ./m , i t i u - i k .
~ i - --
. .
Patterns not included; Muscovite (135), Tremolite (119/120) Dolomite
Most probable minerals present; Chlorite, Talc, Magnesite
Visual Comparison; Minerals Present:
Chlorite, Talc Chlorite, Talc
J&J-0060755
113
SAMPLE 133 TALC END OF WORKING
:V
V.' -
T
\
7
/
.j
'? ) \u
ftt
*
r ft' Jm**A V i t *. `i , mi;Vlk4.
ik
*.**^> ji,
Comparison:
Patterns not included: Muscovite CI35), Tremolite (119/120)
Most probable minerals present: Talc, Chlorite, Magnesite
Dolomite
Visual Comparison:
\
Talc, Chlorite, Magnesite
Minerals Present:
Talc, Chlorite, Magnesite
SAMPLE 136 GREY TALC Comparison: 2 unmatched lines
oo 1.2204A; 1.1517A
Patterns not included: Calcite (134),, Talc (146) Tremolite (119/120).
Most probable minerals present: Chlorite, Muscovite, Talc
Visual Comparison: Chlorite, Talc Minerals Present: Chlorite, Talc
SAMPLE 138 TALC AND PYRITS Comparison: 1 unmatched line
o 1.041A
Patterns not included: Chlorite (142), Chlorite (14), Muscovite (135), Tremolite (119/120)
Most probable minerals present: Talc, Calcite
Visual Cor.oarison: ' Talc, Calcite
Minerals Present:
Talc, Calcite
J&J-0060756
SAMPLE 139 S-- Q 1 FROM CRUSHER
Comparison.
>
Patterns not included: Muscovite, (135) , Tremolite (119/120). Magnesite (16).
Most probable minerals present: Talc Chlorite
Visual Comparison: Talc, Chlorite, Calcite
Minerals Present; Talc, Chlorite, Calcite
SAMPLE 140 PLATEY TALC
Co'mparison:
Patterns not included: Tremolite (119/120)
Most probable minerals present: Talc, Magnesite, Chlorite
Visual Comparison;
Talc, Chlorite,* Magnesite
Minerals Present
Talc, Chlorite,- Magnesite
SAMPLE 141 GOOD SPECIMEN No.2 .
Comparison;
Patterns not Included; Calcite (134), Muscovite (X35), - Tremolite (119/120), Magnesite (16), Dolomite
Most probable minerals present: Talc, Chlorite
Visual Comparison; Talc, Chlorite
Minerals Present: ?alc, Chlorite
J&J-0060757
115 SAMPLE 142 COLOURED TALC No.l.
Comparison
Patterns not included! Magnesite (137), Talc (146), Muscovite CI35), Dolomite.
Most probable minerals present; Chlorite, Talc.
Visual Comparison: Chlorite, Talc
Minerals Present!
'Chlorite, Talc
SAMPLE 143 FIBROUS TALC FACE lO
-r
Comparison;
2 unmatched lines
i" '
:lu OO 4.8928A, 4.4431A
1 1
Patterns not included: Calcite (134), Magnesite (137), Muscovite (135), Treraolite (119/120)
Most probable minerals Present: Chlorite, Talc
Visual Comparison:
Chlorite, Talc
/
Minerals Present:
Chlorite, Talc
J&J-0060758
SAMPLE 144 PURE TALC FACE 1
Comparison; L unmatched line 1.0798
Patterns not Included: Magnesite (137), Talc (.142), Muscovite (.135), Tremlita (119/120)
Most probable minerals present; Chlorite, Talc, Dolomite
Visual Comparison; Talc, Magnesite, Chlorite
Minerals Present: Talc, Magnesite, Chlorite
.SAMPLE 145 ' GOOD SPECIMEN FACE 1
oo Comparison; 2 unmatched lines 1.0882A, 1.0505A Patterns not Included: Calcite (134), Chlorite (142), Chlorite (14) Muscovite (135), Magnesite (16), Tremolite (119/120), Dolomite. Most probable minerals present: Talc,'Magnesite Visual Comparison; Talc Minerals Present; Talc
SAMPLE 146 COLOURED TALC FACE 3
Comparison; Patterns not included: Chlorite (142), Chlorite (14), Muscovite
, (135), Tremolite (119/120). Most probable minerals present: Talc, Magnesite Visual Comparison; Talc, Magnesite
Minerals Present; Talc, Magnesite
J&J-0060759
117
Specimen Patterns and Comparison Data for Samples of Old Powders and 0 0 0 0 0 Shipments
\
J&J-0060760
118
SAMPLE BATCH 6 P O W E R Fl BK.J. 035
Comparison:
1 unmatched line
o 8.1972A
Patterns not included; Muscovite (135), Tremolite (119/120)
Most probable minerals present; Talc# Magnesite, `Chlorite Visual Comparison: Talc, Chlorite, Magnesite Minerals Present: Talc, Chlorite, Magnesite
SAMPLE BATCH 8 POWDER (S and G) PW.J, 035
Comparison Patterns not Included; Magnesite (16) , Tremollte (.119/120) Most probable minerals present: Talc, Magnesite, Boric Acid 'Visual Comparison: Talc, Chlorite, Boric Acid `Minerals Present: Talc, Chlorite, Boric Acid
SAMPLE BATCH 9 POWDER T4 P.W.J. 035
. Comparison: 1 unmatched line
o 1. 2587A
Patterns not included: Tremolite (119/120)
Most probable minerals present: Talc, Chlorite, muscovite, . Magnesite, Boric Acid
Visual Comparison: Talc, Chlorite, Boric Acid
Minerals Present; Talc, Chlorite, Boric Acid
J&J-0060761
119
, SAMPLE BATCH 10 POWDER SKlBP PW.J. 035
Comparison
Patterns not, includedt Calcite (134}, Muscovite (135), Tremolite (119/120), Dolomite
Most probable minerals present: Talc, Chlorite, Magnesite, Boric Acid.
Visual .Comparison: Talc, Chlorite, Boric Acid
Minerals Present; Talc, Chlorite, Boric Acid
-.
' SAMPLE BATCH 11 POWDER LD18P PW.J. 035
o Comparison; 1 unmatched line 8.1363A
Patterns not Included; Magnesite (16) , Tremolite (119/I20) Dolomite
Most probable minerals present; Talc', Chlorite, Boric Acid Visual Comparison; Talc, Chlorite, Boric-Acid, Magnesite Minerals Present; Talc, Chlorite, Boric Acid, Magnesite
SAMPLE BATCH 12 TALC 1960 PW.J. 025
Comparison; 1 unmatched line
o 8.12 A
'Patterns"not included; Tremolite (119/120)
Most probable minerals present: Talc, muscovite, chlorite, Boric Acid.
`Visual Comparison: Talc, Chlorite, Boric Acid, Magnesite
Minerals Present: (Talc, Chlorite, Boric Acid, Magnesite
J&J-0060762
120
SAMPLE BATCH 13 TALC 1961 Ptf.J. 026
Comparison
Patterns not Included: Calcite (.134), Muscovite (135) Tremolite (119/1201
~Most probable minerals present: Talc, Chlorite, Magnesite Boric Acid
Visual Comparison: Talc, Chlorite, Magnesite, Boric Acid 'Minerals' Present: Talc, Chlorite, Magnesite, Boric Acid
*-'*,
SAMPLE BATCH 19 S.S.
.
--
' 'h .it
.
l ) i ( HI i
v v ;4. 4l ;
CATHERINA W. Q2/OS/72
> - . ""T'
'
V.
r
}v
...J..
V-
' " A x\ . . \ ' \ V f;
v. *i *: 1t f.' f: -T*
i' -
.** t s
. 'i j
- -
'i-: > i :.
.-.teta)
Comparison
Patterns not included; Tremolite (119/120)
Most probable minerals present: Talc, Chlorite, Magnesite
>
Visual Comparison: Talc, Chlorite, Magnesite
Minerals Present; Talc, Chlorite, Magnesite
SAMPLE BATCH 2 Comparison
TALC S.S. EDNA *B* 14/02/72
Patterns hot included; Talc (145), Tremolite (119/I20) Most probable minerals present: Talc, Chlorite Visual Comparison; Talc, Chlorite Minerals Present: 1 Talc, Chlorite
J&J-0060763
CONCLUSIONS
121
- -*>-**
The optical examination has shown that there are a large number of minerals associated with the rock types found both in the talc seam and in the associated rocks.
The footwall rocks in contact with the talc are mainly composed of the minerals quartz, muscovite, chlorite, garnet, and some carbonate material both calcite and magnesite. Minor minerals in the footwall contact rocks include epidote, microcline, tremolite and actinolite, sphene, rutile, hornblende, rare talc, biotite, pyrite, pyrrhotite and chalcopyrite. Rock type inclusions into the talc have similar compositions to the footwall rocks but with higher muscovite and chlorite contents. The muscovite was generally an iron rich variety Cphengite), while two forms of chlorite were observed namely sheridanite and penninite. Other talc inclusions consist mainly of carbonate minerals, calcite and magnesite in varying quantities. It is with these nodules that some tremolite is found. The rocks further away from the talc seams, namely the gneiss, become richer in quartz and microcline and below these marble occurs.
The carbonate specimens examined by optical means showed that the carbonate minerals, calcite and magnes ite, were accompanied by talc, chlorite, tremolite, muscovite, rutile and pyrite, all in minor amounts. In general the carbonate inclusions were large and very discrete in the talc seam itself.
The specimens examined, which can be classified as talc samples, were found to be in the main composed of talc with chlorite as the major contaminant. Some specimens, however, were predominantly composed of chlor ite with minor talc inclusions. Other minerals found in association with the talc specimens included garnet, rutile and magnesite with rare tremolite and a quartz or serpentine Inclusion. Some differences were observed in the talc itself, some of the talc appearing to be a little murky in texture. X-ray pictures of the clear and murky material showed no differences however.
The powder X-ray examination confirmad the major minerals occurring in the hand specimens and a classifi cation was possible into the three groups already men tioned, i.e. rock types, carbonate samples and talc spec imens. The only asbestos type mineral to be detected in the hand samples was tremolite, which was found in three of the specimens. The tremolite was associated with carbonate minerals, namely magnesite and calcite, no tremolite was detected in the talc type specimens. Chlorite was, hpwever, very common in the talc types, some of the specimens being very nearly pure chlorite in composition.. There appeared to be some association of
the chlorite with coloured talc specimens, especially those with a greyish colour. Other colour variations due to rutile were not detected by X-ray examination.
J&J-0060764
The examination of consecutive samples at face 1 in the mine showed that the chlorite content can vary very drastically over a 6ft thick section of the talc seam. Patterns obtained from several shipments of 0 0 0 0 0 talc showed that chlorite, together with carbonate material, were the major contaminant minerals. This was also true of powder samples ranging back to 1949 in which the only observable difference was the presence of boric acid.
The electron microscope examination of the powdered samples showed that a difference could be drawn between particles produced from the various samples. The carbon ates and rock types on the whole produced compact fibre free particles. The talc specimens were, however, platelike in appearance with varying quantities of lath like particles coupled with fibres which were textile in appearance. Both lath and textile types of particles were not composed of minerals associated with the commer cial asbestos industry. Particles formed from the amphibole mineral found at the mine were hardly fibrous in character, the majority of the tremolite breaking to give compact particles. Those fibres formed were short . and had a very large diameter when compared with the commercial varieties of asbestos. No amphibole or chrysotile mineral was detected in any.of the numerous powders examined.
The Italian talc 00 00 0 contains observable quantities of chlorite and carbonate minerals and could contain any one of the following minerals in very minor amounts: muscovite, quartz, tremolite, garnet and rutile. If small pieces of footwall rock were to contaminate the ore during production, several of the other listed minerals found in the rock type specimens could appear in the shipped product. It is unlikely that they would be present in detectable amounts.
F.D POOLEY Project Supervisor
l
J&J-0060765