Miscellaneous

The term "asbestos" has been given to six naturally occurring mineral fibers that have been used for commercial purposes. It can be found in hundreds of countries on just about every continent. These fibers belong to two separate mineral groups, known as serpentine and amphibole.

A Detailed Diagram of Where Asbestos Can Be Found in the Home

The serpentine group, usually of a curly form, contains only one asbestiform variety, referred to as chrysotile. The amphibole group, which is straight and needle-like, contains five asbestiform varieties: anthophyllite, grunerite (amosite), riebeckite (crocidolite), tremolite, and actinolite.

The U.S. Bureau of Mines has listed more than 100 mineral fibers as "asbestos-like" fibers, but the United States government only regulates the six aforementioned forms (primarily due to effective lobbying on behalf of the asbestos and stone industries).

These very fine fibers are separable, hundreds of times thinner than human hairs, and too small to be seen with the naked eye. The Occupational Safety and Health Administration (OSHA) defines fibers of concern as at least five micrometers long and at least three times as long as their diameters. For a frame of reference, mineralogists work with fibers as much as a thousand times as long as their diameters.

from [asbestos]