Mica, Pyrophyllite

This is one of the mica minerals that is in the sand from the Palm Desert area. This grain has a 2V of about 58 degrees.

Transmitted Circular Polarized Light

Definition/Function:

Muscovite is a sheet silicate with the general chemical composition indicated as
K₂Al₄ [Si₈O₂₀](OH)₄. It is a relatively rare mineral.

Significance in the Environment:

Characteristic Features:

Pyrophyllite is colorless in thin section, has a 2V of 53-62 degrees, a birefringence of about 0.01 when view normal to its perfect cleavage plane and has a negative optical sign.

Associated Particles:

References:

Deer, W. A., R. A. Howie, and J. Zussman, AN INTRODCUTION TO THE ROCK-FORMING MINERALS, ISBN 0-582-30094-0, pp. 324-326, 1992.