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Identification of Minerals Associated with Asbestos by X-Ray Diffraction Patterns By M. S. BADOLLET* and J. P. McGOURTY (Annual General Meeting, Vancouver, April, 1958) (Transactions, Volume LXI, 1958, pp. 169-174) Introduction als which the chemical analyses in dicate to be present. IT HAS LONG been customary Dr. Cooke was very co-operative for chemists to analyze samples in furnishing us with samples of of asbestos and their associated material identical to those he used rocks by routine chemical proce in his studies. We accepted his dures. Results of these investiga chemical analyses and his re-east tions are usually reported in the minerals data and have applied the conventional way, i.e., the percent X-ray technique for checking and ages of the various constituents identifying the minerals actually existing in the sample under investi present in the samples. The dual gation. Often an examination of the purpose of this investigation was, data shows that re grouping of the first, to explore the limits of the chemical analyses and re-calculation X-ray diffraction method for iden of the data in terms of minerals will tifying the minerals; and second, shed more light on the true com to develop a simplified technique position of the sample. for applying this information in The late Dr. H. C. Cooke in his G.S.C. Memoir 211 (1) presented an exhaustive study of analyses of asbestos and rocks taken from the Thetford, Disraeli, and eastern sample identification. Such a tech nique would be of great value to company geologists in searching for new asbestos deposits, as well as in the examination of drill cores. half of Warwick map-areas in the Province of Quebec. Also he dis cussed the composition of asbestos X-Ray Technique Employed and other fibres of the Thetford district in a paper he presented to the Royal Society of Canada in 1985 (2). Both papers include a series of analyses of fibres from the chemical point of view. The an alyses are accompanied by a re cast of the data in terms of tninerr als in which Dr. Cooke sought to The X-ray pictures were taken by the Noreleo X-ray diffraction unit with a Debye-Scherrer camera for a four-hour exposure, using cop per radiation with a nickel filter. All samples were carefully powd ered in an agate mortar before they were examined in the unit; deduce the mineral composition of each sample. Thifl presentation of data was well dope*. It has been stimulating to the X-ray specialist The X-ray pictures accompany ing this paper carry the following identifications: who is interested in carrying the investigation further to confirm the predictions of the chemist, miner alogist. and geologist, and to make definite identification of the miner * Section Chief, tResearch Engi neer, Johns-Manville Research-Cen ter, Manville, New Jersey, U.S.A. (1) Cooke, H. C., Mem. 211, Geol. Survey, Dept, of Mines and Re sources, Ottawa, 1937. (2) C'Ooke, H. C., Roy Soc. Can., Trans., Sec. IV, 3rd Series, Vol, XXXIX, 1935. A Line S--Serpentine........................ C--Chrysotile........................ A--Antigorite........................ B--Brucite............................. F--Iron oxide....................... G--Grammatite (tremolite) .. E--Epidote............................ Q--Quartz.............................. 2.49 2.44 2.53 2.35 1.61 8.4 2.9 3.34 When doubt existed in identifica tions, it was necessary to adopt spectrographie and petrographic tech niques. Discussion of Data Sample 1* Sample 1 represented a "normal red-weathering serpentine from a chromite pit in the northwest corn er of lot 19 N.W., Range X, Coler aine township". The chemical an alysis (Table I) revealed that it contained SiOa, MgO, and HsO, with small amounts of other metals. Re-casting into minerals by Dr. Cooke indicated that the sample was mainly serpentine rock. The reddish colour probably was due to weathering of the small amount of iron present. During recent years the X-ray diffraction patterns of serpentine have been fairly well indexed and identifications have been made easier. The pattern of Sample 1 showed clearly the typical ring structure of serpentine with a con siderable amount of crystalline brucite. These two diffraction lines are identified in Figure 1. The chemical analysis showed an excess of MgO over the amount required to combine with Si02 to form serpentine, H1Mg3Si20(1; this excess of MgO crystallized in the form of brucite, Mg(OH)2, which is intimately associated mechan ically with the serpentine. The asbence of evidence in the dia gram of the presence of other minerals is due to the fact that any compounds formed by the minor constituents shown by the chemical analysis are not in suffi cient quantity to yield definite Xray diffraction patterns. The brucite is so closely associated with the serpentine that it could not be re moved by mechanical means but it could be dissolved out chemically. `The descriptions and chemical analyses of samples 1 to 21 are re produced from GJS.C. Memoir 211, by Dr. H. C. Cooke. Numbering of the samples is the same as in that report. -- 44 UCC 004636 "' Sample 2 Sample 2 represented the same material as in Sample 1, but it ex hibited "material blackened over a zone a foot wide, and flanking a dyke about a foot Wide". Chemical analysis (Table 1) showed the presence of A1303j Fe203, and FeO in quantities that indicated other minerals than serpentine must be present as impurities. The X-ray diffraction patterns did not reveal the presence of brucite, thus confirming the chemical analysis, which showed sufficient SiOa to combine with all the MgO to form serpentine; hence, no ex cess MgO remained to form brucite or any other magnesia mineral. Al though the chemical analysis siiowed the presence of aluminum and iron compounds, they were not identified in the X-ray pattern be cause they are present only in very small amount. Sample 3 Sample 3, which represented "chrysotile asbestos taken from the King mine", is typical of the fibre from that area. The chemical an alysis (Table 1} disclosed a com position equivalent to that of chrysotile asbestos, with small traces of impurities. Dr. Cooke, in his re-calculation of the analysis, deduced the possible presence of minerals such as chlorite, talc, and periclase as impurities associated with the chrysotile asbestos. X-ray diffraction lines did not indicate the presence of brucite, but they did show a trace of quartz. Al though the chemical analysis, when re-cast in terms of minerals, indi cated the presence of chlorite, tal% and periclase, lines for these miner als were not visible in the X-ray pattern. ' ag;.,,. " This sample Wftn also analyzed quantitatively by emission spectro scopy* with known oxide mixes as standards; the data obtained, on an ignited basis, showed the presence of Al,0:l, 0.10%; Fe203, 1.3%; and CaO, 0.11%. if the iron in the orig inal sample was in the form of Fe.O,, it would have been oxidized to Fe203 by the treatment pre ceding to the spectroscopic examin ation. The total amounts of AL03, Fe203, and CaO by spectroscopic Tablb f.--Analyses, Samples 1 to 4 JL SiOj--. AljOgi.. F*20a->' FeO.... CaO ... MgO . H2O+HjO* * * * T102 - MnO .... coa .... CraPa... mo.... - 34.40 0.50 0.82 3.79 0.02 42.36 15.17 0.47 mi 0.94 0.3a 0.48 0-35 Total- 99.68 X 40.42 2.24 2.11 4.26 0.29 39.44 11.11 0.10 J 42.05 mi 0.96 0.39 0.05 43.30 12.52 0.75 99.97 100.02 + 43.48 1.41 0.60 2.36 0.12 39.50 12.69 0.45 IX. 61 Figure 1. S--serpentine line; B:--brucite line. Figure 2. S--serpentine line. m i 1 Sampti tile fibre .... .. i table. ';*? i1 j which. _ brittle appaeehi^'byj tbe blackened yms. *. sons close HrtJmia<^dyIEb''', Thfc - V-- Hn-|M * 3-1 chemical analysis (Tabki I) indl-: cated chrysotile asbestos, with AljO, and FeO and an excess of SiOj present The data, when re cast into minerals, showed the pos sible presence of chlorite, brueite, and silica. ' . /'"s ' _ s- ' ' The X-ray diagram didnobshow bracite, silica as quarts, or Chlorite. The chemical analysis, however, in dicated an excess of SiO, over the a* -t to . ' jt.: . , C-^chrysotBe ttne,- amount required by tbeMgQ to1 form asbestos: Thm SiOj may have' been in the form o. amorphous. If* SiO, which would not show in the X-ray diagram;,oniifmay h^Tc beei*: # in combination witlf tfhe- tnibor can-* stituents shown byr tito j cbltoifeal: analysis, and the cbmponndff tbna formed are not in sufficient quan tity to produce an X-ray diagram. The X-ray film did indicate iron as Fe,0* or Fe>Ot. _ Emission spectroscopy' of thin sample showed * th# presence*dfe v--i - v*v--,-?-.r VigotoK : . *- V..-.AX* line^F- wnh.rMqAj'i gr^V-W' AlaQsi 0 2d% ; CaO, 0.08%. Thbse spectroscopic' data did not agree -v`--' 1 ical analysis, again difficulty of id minerals present ^icnrpif'r* A; -v-ML Sample 7 Sample 7 reipresented:: "high-grade chry* taken from the chemical minor ami '.tj^3Fav^ ;., rninum, posag presence af~ re-cast data cite, and pte The X-ray ? _ snSir lines for bnw&i^l^pj^ . `to- pe? close; although the sis indicated a slight eXeesS- nf hj|{^} X it was not identified: in the: X-ray , diagram. Iron a*:FtQ^ in the X-ray dsgjr|in: spectroscopy showed toe presesee'd^v' AlsO,, 0.12 % - Fer,,,,jt,70%; W CaO, 0.08%. , ; sf " -V-;: "f, ...,,, p^ tfifv * rT'. -? Fipus *t >-,<3' 'O.'i^WS-S . ' .5 > }lf - . Sample, a> v:^''-3v Sample 8 represented a "highgrade chrysotile asbestos taken UCC 004638 . . .-. ' O' -\ieb4. . ' ;: figure 11& p 1 ' C--chrysotile line; F--iron line. 46- *5?a f'.-A* .Af-JVfcfpgj `xrV from Deloro township. Province of Ontario ". The chemical analysis (Table II) showed the presence of impurities. The re-cast data indi cated the possible presence of chlorite, talc, and periclase. The X-ray diagram did not show chlorite, talc, brucite, or periclase. If these minerals were present, the quantities were insufficient to pro duce an X-ray diffraction pattern. Emission spectroscopy demonstrated tile presence of A1203, 0,07%; Fe2Oj, 1.0%; and CaO, 0.02%; amounts which differ from the chemical analysis. Sample 9 Sample 9 is a chrysotile fibre from the "British Canadian mine at Black Lake". The fibre is further identified as a semi-harsh type, i.e., not actually brittle, but not soft and silky. The chemical analysis (Table II) showed small amounts of A1803, Fe20.(, and CaO, and almost 2 per cent FeO. Calculated in terms of minerals, the presence of chlor ite, talc, and periclase was indi cated. The X-ray diagram did not re veal the presence of brucite, chlorite, or periclase, but it did show small amounts of FeaOi. Emission spectroscopy showed the presence of A1203, 0.16'%; Fe/L, 4.0%; and CaO, 0.02%. If Fe.O, were present originally it was probably oxidized to Fe3Oa by the ignition process in preparing the fibre for this test. Sample 10 Sampie 10 is an extrardinary chrysotile asbestos fibre of harsh texture bordering upon a brittle nature. It is from the "Vimy Ridge mine in Coleraine township". The chemical analysis (Table II) indi cated a low MgO-SiOi ratio, a low combined water content, as well as a high percentage of Fe203. Re cast in terms of minerals, the pres ence of chlorite, talc, and periclase was indicated. The X-ray pattern did not show lines for brucite, talc, periclase, or chlorite. If these minerals were present they must have been in very small quantities, not detectable by the X-ray technique. Emission spectroscopy showed Al-.Oa, 0.52%; Fe203, 3.0%; and CaO, 0.03% ; amounts which do not agree with the chemical data. Table II.--Analyses, Samples 7 to 10 3102... 4120* F0 * .. ClO * i ' * K*0 - HjOf... H2O------ 7 W..13 o.ao 1.01 0.58 0.03 43-24 12.74 0.45 Totals- 99.98 S 42.40 0.14 0.97 0.19 0.14 43.09 12.60 0.45 99.98 41. DO 0.64 0.80 1.89 0.14 42.18 12.07 0.20 99.72 /O 42.95 *11 2.08 0.84 0.19 41.60 10.26 1.61 99.53 Figure 11. C--chrysotile line. Figure 12. B--brucite line; C--chrysotile line (barely visible). Figure 13. B--brucite line. Figure 14. C--chrysotile line; A--antigorite line. -- 47 -- UCC 004639 Figure 15. C--chrysotile line. 4 \ 4 < <* '*i* fr- Ifc:- orar] itfr *`T $? o* .W:. v>' . iSSt iflf i-ffetettM! of minerals, 9te, and periclase were Jo __ The X-ray dfcigr!^'. showed no trace of brncite, / periclase,, or chlorite; however, the' diffraction lines for chrysotile and iron are clearly defined. -. Sample 16 Sample 16 is another specimen of "slip serpentine taken fromha fault-aone indriffrSOtX of the King:; ,' mine, Thetford";. The analyst" (Table III) showed that the SiO, ^ was slightly low, and the MgO rath- er high, for serpentine. Minor con- i stitnents were Al2Os, FeaO,, FeO> 1 and COj. The data, re-cast as min erals, suggest the presence of chlorite, brncite, and Uydromagne- site. .. ' V **' . ... ... The X-ray diagram showed :*n0;:, trace of brncite, chlorite, or hydro-' magnesite. It did:* show, however, chrysotile, and iron as Fe,0. Mpr >7 t&< -.u &:$&<r-*reS : *rem*dlP :*.* r liM c.f :/,04*. UJrt \ 1.3* *.# ?" i. rt * ft?1J* ioo.}* 100.00 ioo.to 100.75 | "i-l r}P w" it'#-"" >* 5''*J4 - 0.W MOJ* JgP ^ ,a3w-^r:- '* ^Ti~ .'"si ' .? Figure 16.CJfi-bprj'sotile line; BU--hrtieito line.- 'L -* -- v , * . --- q> Sample 17 . : *V'J V Sample 17 represented, a "tough,.*, stite fine; EM-epidotfe line:. stringy fibre from a. fault, driftf" '* W- **t .j4r*-a C502E, near D 606X, King mine, No. ' I It)?SiO* hmT Mg&; the cMefeon- ' Thetford". Chemical analysis, (Table t - III) showed substantial amount*^1 of FeaOs and FeG, Re-cast of the* , analysis in terms of minerals ihdlr- cated the presence of chlorite, hits* , cite, and periclase. The X-ray digram; trace of chlorite, brncite, or' clase, but the chrysotile dfiiei defined. , 1}W ie ,. stituent'^:`.*ere m abont the rfgh^- fdiagram. proportion. tft form serpentine," but '"a , tho presence of relatively large SjK 'fibre talf- .arThet(Tbbfe. amonnti bf Ferffe and FeQ suggest-. -^c.V ed an admixture of other minerals. Re-calculated data, indicated the : presence of chforite, taje, periclase, m and hydromagnesite. ., ^ faniLCaO*, Tin X-ray. diagram- showed tfte " " e of m^teriat W tie gorite. No _ -yraa,.. Sample 18 asbestos fibre, King mine, further identifii a fault fibre. , ^ , va_ (Table III) showed rt&tireJ^__ __ than r*ej<sid. .t*iVhi o erve-d" 'about Wtf*her with ,P*rdase, observed, ' , > i ' ; 2&1"" ` ' Sample 2irwas described as a* "semi-fihrous pireolite filling vefiL . at the 30^feot , lb7^ ^ the bg".: amounts of Al:Os, Fe,Oi, and FeQij:; indicating considerable containinap' tion, SiOj was extremely Jow, H,<5 dDkgAmt ' showed that , . was- * very high, and MjgO unnsualty indicating a peculiar fibre composfc!. eyidbHsfe,: . . tion. Re-calculated data indicatad mine at Thetfird1^ fjhmnical .an- - alysis s&we^ CEagli thi* It.. contained appijeemble amoxmts of , presence. A ether mineral* than plcrol}te.' Btfbait & the* analysis'in- 3^l; that the minerals present might be " ^h'4iprita brncite, chlorite, and perielase, with ' brncite comprising 87.61 per cent . Sautjdffi r 'a*- a " /e (red JSSW' i T of the sample. This is an interest ^ l^iceh from diagram did not show ing sample for farther Investigation!' a ftmlt 'ij^ne kt tHis' UOO-fbot level lines for bruclte, chlorite, talc, or The X-ray diagram showed a in the Xing mine in Thetford'*. periclase, bat it did show the dif very high percentage of brncite, Chemical analysis showed ((Table fraction line for chrysotile. UCC 004640 -- 48:, .1 i. i r *' 3(5% ,,j- < :' M9S' -- ' Sample 50 was described as a "tough stringy fibre forming cross fibre veins at dfilit 505X in the Xing mine, ThetfBEil^, It was more specifically as a soft- chrysotile fibre. :al analysis (Table IV) showed the presence of A1203j Fe203, FeO, and CaO, as well as a small amount of NaaO and q Re-cast by Dr. Cooke in terms of mineral composition the analysis indicates that chlorite 8.01%, and brucite 9.19%, may be associated with the chrysotile in this sample. The X-ray diagram disclosed the presence of chrysotile and brucite, but no chlorite. Sample 63* Sample 68, described as "pseudo asbestos", represented fibrous veins in the footwall of the Federal pit near Robertsonviile, Quebec. The analysis is given in Table IV. This specimen was an interesting sam ple for X-ray analysis since it showed a high percentage of A1203, FejOj, FeO, and CaO, with MgO exceedingly low. The X-ray diagram showed lines corresponding to grammatite (tTe- molite) and epidote. Conclusions Chemical analyses of chrysotile, picrolite, and other varieties of ser pentine invariably, or almost invari ably, show that, in addition to the MgO, SiOj, and H20 necessary to form chrysotile of theoretical com position H,Mg3Si208, they contain *The descriptions and chemical analyses of samples 60 and 08' are reproduced from the paper buDr, H. C. Cooke in Volume XXIX, 1936, of the Transaction*-# the Royal So ciety of Canada.- Mstmbering of- the samples is the sao^pa`i>. that paper. i/*=>: *. Table IV.--Analyses, Samples SO and63* Sample 50 SiGa............ AI,03........... FejOs.......... FeO............. CaO MrO............ H20+......... HjO--......... TiOj............ NiO............. NaiO........... KsO............. 37.44 0.58 1.23 0.54 0 20 43.49 14.60 1.71 -- 0.28 0,05 100.12 Sample 63 46.36 11.39 9.30 3.18 18.47 8.94 1.87 0.12 0.05 flfil 0.15 -- -- 100.44 also a small, or in some specimens a very appreciable, percentage of AljOs, Fe203, FeO, etc. By re-cast ing the analyses in terms of miner als these may be assigned to various minerals such as brucite, chlorite, perielase, and hydromagnesite, which may or may not actually be present admixed with the chrysotile. Except when in very small amount, definite verification of the presence of one or more of these minerals can be made by application of Xray diffraction, emission spectro scopy, or petrographical methods of examination. These methods, and in particular the X-ray diffraction method, have been used in the pres ent investigation of specimens of serpentine from a number of asbes tos mines in the Eastern Townships of Quebec, and of one from Deloro township, Ontario., A critical study of chemical, and re-cast mineral, analyses of the specimens had been made earlier by Dr. H. C. Cooke, who very kindly supplied the writ ers with the material used in their , investigation. For some specimens, the X-ray diffraction patterns confirmed the mineral composition as derived by Dr. Cooke in his mineral re-cast of the chemical analysis; for some others, in which the extraneous min eral or minerals were in very small amount, diffraction lines for these did not appear. Clearly, with a sam ple containing two or more minerals, only those present in sufficient quantity to give diffraction lines can be definitely identified as being pres ent. Samples of the latter type were analyzed by emission spectroscopy and in a general way, though not quantitatively, the results were in agreement with those derived by Dr. Cooke from his study of the chemical analyses. Petrographic ex aminations under the microscope were also helpful in cases where doubt existed. This investigation has indicated that no one method is adequate in itself for complete and positive identification of all the minerals present in a sample. For this it is necessary to resort to a combination of several methods. For complete identification of all the minerals present in samples obtained in pros pecting or in drill cores of asbes tos bodies, not only chemical an alyses but alsu the results of X-ray diffraction, spectrographic, and' pe trographic studies are necessary. Acknowledgments Chemical data used in this paper were taken from G.S.C. Memoir 211, by the late Dr. H. C. Cooke, and from a paper by him in the Transaction* of the Royal Society of Canada, Volume XXIX, 1936. This investigation was initiated six years ago after a discussion with Dr. Cooke, in Ottawa, on the use of X-ray technique for identification of minerals. Dr. Cooke supplied all samples used in the investigation. The assistance of Mr. Charles Whinfrey, formerly of the JohosManville Research Centre, who made the preliminary X-ray studies, is appreciated.