Amphibole Asbestos Mines In California

Small seams of fibrous tremolite and actinolite commonly occur in many California counties. A number of larger seams of this fibrous material were mined from 1882 until about 1955. The fibers from these mines were used for making acid filters, battery cases and fire-resistant paint. With increasing population, new residential areas are being developed in the foothill regions, leading to increased contact with seams of fibrous amphiboles. These forms of asbestos can be particularly dangerous to human health. Thus, it is necessary to determine the locations of these mines and adjacent veins and to identify the specific amphibole minerals present.