Mica, Muscovite

This is one of the mica minerals common in the sand from the Palm Desert area. This grain has a 2V of about 45 degrees

Transmitted Circular Polarized Light

Definition/Function:

Muscovite is a sheet silicate with the general chemical composition indicated as
K₂Al₄ [(Si₆Al₂)O₂₀](OH,F)₄. It is a very common mineral.

Significance in the Environment:

Muscovite has a number of industral and comertial uses as well as being a common natual mineral. Its transparecy and thermal and elecrical insulative properties result in its wide use in special lamps, electric fuses, furnace windows, etc. Its shape makes it especially susseptable to airborne transport.

Characteristic Features:

Muscovite is colorless in thin section, has a 2V of 28-47 degrees, a birefringence of about 0.005 when view normal to its perfect cleavage plane, 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. 288-293, 1992.