Document LJJjgnzNKLB267j9X4jLGBkxX

FILE NAME: Railroads (RR) DATE: 1929 Apr 8 DOC#: RR072 DOCUMENT DESCRIPTION: Excerpt from American Mining Congress Special Daily - Mineral Deposit, Discussing Discovery of Vermiculite G w PS"^ jZii^ .. THE AMERICAN MININQ CONGRESS SPECIAL DALLY INFORMATION SERVICE, HASHINGEON,DC. April 8, 192?. Tol. X. - No. 81 MINERAL DEPOSIT During the World War a prospector searching an old tunnel near Libby, Montana, noticed flakes of a coarse mica-like mineral that writhed and swelled enormously when touched by the flame of his candle. The flaky mineral, according to a statement by the Geological Surrey, proved to be vermiculite, and further examination showed it to be present in great quantities. The name vermiculite is applied to a group of minerals that expand and give off water upon heating. Some mem bers of the group thus open into long, worm-like threads, hence the name. The heated and expanded material is very light, exhibits a golden or silvery luster, and appears to have very low heat conductivity. These properties suggest possibly important commercial uses. The vermiculite deposit near Libby, which is more extensive than other known similar deposits in this country, is accompanied by asbestos and feldspar in considerable quantities and b other interesting minerals, one of which carries small percentages of vanadium, a metal that is useful as an alloy in certain types of steel. A report on this deposit, under the title "Deposits of vermiculite and other minerals in the Rainy Creek`district, near Libby, Montana," by J. T. Pardee and E. S. Larsen, has been published by the Survey. rS)