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/1 /i ^ 54 Asbestos Fundamentals cates the presence of intergrowths or of accompanying minerals; their nature can be deduced from the magnitude of these supple mentary periods. Within the nniphibolc group, the individual kinds of asbestos can even be differentiated visually on the basis of the number of reflections (2-layer line). If the specimen of asbestos is not in the form of well developed long fiber bundles, it is necessaty to prepare Debye-Scherrer powder diagrams, such as the one shown in Fig. 20, for which the fibrous "P 2" chrysotile used in the fiber diagram shown in Fig. 24 was pulverized to make a comparison possible. Through superimposed Debye-Schcrrcr powder rings, fiber diagrams can indicate the presence of asbestos dust at like identity periods, whereas supplementary periods point to the presence of pulverulent accompanying substances (foreign mineral or rock powders, magnetite, sand, etc.). The width of the reflection can be employed to deduce the degree to which the fibrous structure has developed. f o o o o & o >o Tm. 26. Debte-Scherrer Powder DirmAcnos Pattern or Ural Cbrtsotilb (P2) LITERATURE 1. M. 3. Badollet and J. P. McQourty, Identification of mineral* associated with asbestos by X-ray diffraction patterns, Trans. Can. but. Mining Met., 61:160-174 (1958). 2. O. Freyer, Roentgenogrsphbehe Untersuchung rerachiedener Asbestftsn, Witt. Z. T. H. Dresden, 3, No. 2:147-49 (1953/54). g. J. Teehel u. O. Freyer, Snwjctlseher Aebest, Sffikattechnik, 4, No. 9:403-09 (1953). 4. E. J. W. Whittaker, The structure of chrysotile, Ada eryttallogr. (Copen hagen), 6:747-48 (1953). 6. W. Noll n. H. Krcher, Ueber die MorpHologie von Asbesten und ihren Ztaammenhang mil dcr Kristaltstruktur, Neue Jahh. Mineralog., JfatafwA., 1951, No. 10:219-40. 6. H. Jsgodtinskl u. S. N. Bagchi, Die gerotlte Struktur des Chrysotils, Neat* Jahrb. Mintralog., Monafoeh., 1953, No. 5/857-100. 7. H. Jagodsinski u. G. Runic, Die R6llchcnstruVtur dcs Chrysotils, Hid., 1954, No. 4/555-108; No. 0:11.1-30; No. 7:137-50. 6. H. Wondratschck, Orienticrle Vcrwsehsungen von Chrysotil mil Mincratien derScrpcntin-Cruppc und mit Kalzit, tfitVf., 1957, No. 6:135-40. Properties or Asbestos 55 9. T. F. Bates, Morphology and crystal chemistry of 1:1 layer lattice sili cates, Amtr. itintrelogitS, 44:78-114 (1959). 10. T. F. Bates and J. J. Comer, Further observations on the morphology of chrysotile and haltoysite, Proc. 8, Nat. Conf. Clays and CIny Minerals, No. 55/57237-57. 6.2 Chemical composition The chemical cj-"'position of the asbestoses is likewise depend ent on the asbestosgroup, and within the amphibolc asbestoses on the variety, and among all asbestoses (of the same kind) eventually also on their origins (occurrences). See Fig. 23. A tabulation based on occurrence with a statement regarding the individual tolerances for all members of the entire assembly has but little significance from a practical standpoint and this is why Table 4 gives only a general view, which takes into consideration the differences in the values arising from the various localities from which the specimens came. The analytical data of most importance industrially are always those stating the found values for the proportion of water and content of iron oxides. Tarue 4 PERCENTAGE COMPOSITION OF ASBESTOS Variety Chrysotiles * Crocidolite* Amosites Montasites Anthophyllite (bestows TVsmolite- and Aetinolite asbestoses SiO, 35--44 49--57 45--58 MgO Iran oridtt Alfi, 36-44 0--9* 3-15* 20*--10* 4-7 31--48* CaO No/) 0--2 2--8 1--2 52--64 25-35 1--10 0--1 50--63 18-33 2--17 1--19 12-15 2--4 1--3 1-6 1--4 ' Tba water mint aboold not txrquaUd *{tb lb* Iw os Ignition. 9 Cwb- ssd toQfjtadioAl Ibm. Tha emteat nt Baga*tita(FaA> may ba u Mch u FJ. lb, tootrot of F0 aod TttO, mar naeb 9% aoeb. tba ratio F,0/F,|0, ririn batorro 0.3 and S.O. Tbo bright bloc erocUoUtea from Bolirte aod China with hlghor MgO- aad lowrr Iroo mtoot emaaoZ bo tvsardtd ao oaowtUraaBd hoarr tbrj- tttrt iorludtd heia. Tba proportion of (too III) la around 00% in crocidoUta; about 90% la anoaita. The water content is indicative for the division into chrysotilcs (average 14^) and amphibole asbestoses (average 2%). Among the amphibole asbestoses, the blue varieties are recognizable PRODUCED BY FORD