This sample is from the white paint layer on the surface of a cellulose fiber acoustic
ceiling tile. The sample is mounted in high dispersion 1.605 refractive index oil and a single linear polarizing filter
is oriented perpendicular to the length of the fiber. The wavelength match here is about 590 nanometers. That indicates a
D-line refractive index for the anthophyllite of about 1.605
Transmitted Phase Contrast with a Single Linear Polarizer Perpendicular to the Fiber Length
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%.
Anthophyllite has refractive indices that overlap those of Tremolite and Actinolite asbestos but Anthophyllite always shows
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.
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
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