Anthophyllite Asbestos
This is an Anthophyllite from New Jersey. The sky blue
color here with darkfield dispersion staining indicates a
refractive index match in this 1.605 high dispersion liquid at a wavelength of about
640 nanometers. That indicates a
D-line refractive index of about 1.604 for this fiber.
Transmitted Oblique Darkfield Dispersion Staining, Single Polarizing Filter
Perpendicular to Length
Definition/Function:
Anthophyllite asbestos is a fibrous amphibole with the chemical composition
(Mg, Fe)7[Si8O22](OH, F)2. It is one of the
more hazardous forms of asbestos.
Significance in the Environment:
Anthophyllite had a rather limited commercial use and is encountered as an impurity in
talc as often as it is as an
intentionally added material. In materials with a significant talc content the amount of
Anthophyllite can exceed 1%.
Characteristic Features:
Anthophyllite has refractive indices that overlap those of Tremolite and Actinolite
asbestos but Anthophyllite always shows
parallel extinction.
Associated Particles:
As an impurity it is generally found with high concentrations of talc. It was used as an
additive in paint and ceramics,
mastics, floor tiles, acoustic tiles, and other construction materials.
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. 232-236, 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.