Magnesian Crocidolite
Transmitted Off Crossed Circular Polarized Light Illumination
2. Campbell, W.J., R.L. Blake, L.L. Brown, E.E. Cather, and J.J. Sjoberg, IC 8751; SELECTED SILICATE MINERALS AND THEIR ASBESTIFORM VARIETIES, US Dept. of the Interior, Bureau of Mines Information Circular, 1977
3. Deer, W. A., R. A. Howie, and J. Zussman, AN INTRODCUTION TO THE ROCK-FORMING MINERALS, ISBN 0-582-30094-0, pp. 261-267, 1992
4. Ledoux, R. L. (ed), SHORT COURSE IN MINERALOGICAL TECHNIQUES OF ASBESTOS DETERMINATION, Mineralogical Association of Canada, 1979.
5. Levadie, Benjamin (ed), DEFINITIONS FOR ASBESTOS AND OTHER HEALTH-RELATED SILICATES, ASTM STP 834, 1984.
6. Riordon, P. H. (ed), GEOLOGY OF ASBESTOS DEPOSITS, Society of Mining Engineers, 1981.
7. World Health Organization, ASBESTOS AND OTHER NATURAL MINERAL FIBRES, Environmental Health Criteria 53, 1986.
Definition/Function:
Magnesian Crocidolite asbestos, the blue asbestos, is a fibrous amphibole with the chemical composition Na2(Mg,Fe)5[Si8O22](OH) 2. It looses some of its blue color but is still one of the more hazardous asbestos minerals.Significance in the Environment:
Crocidolite is the third most common commercial asbestos, behind Chrysotile and Amosite. It is used in the blue ceramic water pipe that was used widely in the past. It was commonly used in high temperature environments, like boiler. It is the only asbestos other than chrysotile that can be easily woven into cloth. It is rare as a natural mineral so when it is found in an environment it is usually the result of the degradation of an asbestos containing construction material.Characteristic Features:
The blue color of Crocidolite is less intense with the substitution of magnesium for some of the iron but the fibers are still clearly blue. Magnesian crocidolite has refractive indices, around 1.66. The dispersion of the birefringence that is evident in the iron-rich crocidolites is much less evident with less iron.Associated Particles:
Crocidolite is often used with Chrysotile asbestos.References:
1. Asbestos Textile Institute, HANDBOOK OF ASBESTOS TEXTILES, 3RD EDITION, 1967.2. Campbell, W.J., R.L. Blake, L.L. Brown, E.E. Cather, and J.J. Sjoberg, IC 8751; SELECTED SILICATE MINERALS AND THEIR ASBESTIFORM VARIETIES, US Dept. of the Interior, Bureau of Mines Information Circular, 1977
3. Deer, W. A., R. A. Howie, and J. Zussman, AN INTRODCUTION TO THE ROCK-FORMING MINERALS, ISBN 0-582-30094-0, pp. 261-267, 1992
4. Ledoux, R. L. (ed), SHORT COURSE IN MINERALOGICAL TECHNIQUES OF ASBESTOS DETERMINATION, Mineralogical Association of Canada, 1979.
5. Levadie, Benjamin (ed), DEFINITIONS FOR ASBESTOS AND OTHER HEALTH-RELATED SILICATES, ASTM STP 834, 1984.
6. Riordon, P. H. (ed), GEOLOGY OF ASBESTOS DEPOSITS, Society of Mining Engineers, 1981.
7. World Health Organization, ASBESTOS AND OTHER NATURAL MINERAL FIBRES, Environmental Health Criteria 53, 1986.
