Chrysotile Asbestos, Mountain Leather
This sample of mountain leather was found in the Cascade Mountains of Washington State.
Definition/Function:
Mountain Leathers are natural felts of fibrous minerals. They tend to be found on steep, wet slopes in the mountains or along the banks of mountain streams. Common mountain leathers include felts of the asbestos minerals and fibrous clays.
Chrysotile asbestos is the fibrous form of the mineral lizardite of the serpentine group of minerals. Its chemical formula is Mg3[Si2O5](OH)4 with some Fe2+ substituting for Mg. The amount of iron substitution affects the refractive indices and the birefringence. This is the most common form of asbestos used commercially, comprising about 93% of all the asbestos mined. It is also the least hazardous of the asbestos minerals. It is the most flexible of the asbestos minerals and is the one typically used in making asbestos cloth and asbestos paper.
