Asbestos is the name for a group of naturally occurring silicate minerals that can be separated into fibers. The fibers are strong, durable, and resistant to heat and fire.
There are several types of asbestos fibers, of which three have been used for commercial applications: (1) Chrysotile, or white asbestos, comes mainly from Canada, and has been very widely used in the US. It is white-gray in color and found in serpentine rock. (2) Amosite, or brown asbestos, comes from southern Africa. (3) Crocidolite, or blue asbestos, comes from southern Africa and Australia.
Amosite and crocidolite are called amphiboles. This term refers to the nature of their geologic formation.
Other asbestos fibers that have not been used commercially are tremolite, actinolite and anthophyllite, although they are sometimes contaminants in asbestos-containing products.
Asbestos Page - The California Geological Survey (CGS) provides information on the geology of asbestos occurrences in California to a number of state, local and federal agencies, private industry, consultants and the public.
