asbestos, including one small past producer of massfiber tremolite asbestos in Utah−the Tremolite no. 1 mine. In the Southwestern, tremolite and actinolite are commonly reported in the contactmetamorphic (skarn) zone of metallic ore deposits, which formed where an igneous body intruded and metamorphosed a magnesiumbearing carbonate rock.
The hand cobbing asbestos mining operation involves releasing fiber from the asbestos ore rock by means of manually (by hand) hammering away the rock from the ends of fibers. This type of fiber is not processed through the standard crushing units during the milling operation of the shorter filers. See Figure at left.