Collier's New Encyclopedia (1921)/Asbestos

ASBESTOS, a variety of hornblende, Asbestos is exceedingly infusible, at least in a mass. It contains a considerable percentage of magnesia in its composition. It occurs mostly in serpentine districts. The varieties are: (a) Amianthus, in which the fibers are so exceedingly long, flexible, and elastic, that they may be woven into cloth. (b) Common asbestos, with the fibers much less flexible. It is heavier than the first variety. It is dull green, sometimes pearly in luster, and unctuous to the touch. (c) Mountain cork, light enough to float on water. (d) Mountain leather, also very light, but thinner and more flexible than the last. (e) Mountain paper, a designation formerly given to fine, thin specimens of mountain leather. (f) Mountain wood, which, in the external aspect, resembles dry wood. In the United States it is found principally in California and Georgia. Manufacturers draw their chief supply from Canada.

Source: Collier's New Encyclopedia 1. (1921) New York: P.F. Collier & Son Company. 289 (text) and after 60 (illustration).