Occurs in masses or beds, looking much like hard brown earth; loose or porous and earthy, rather than compact and nodular; powder yellowish-brown; when strongly heated becomes black and magnetic; gravity nearly 4. An earthy yellow variety is called Yellow Ochre.
Value.—An important ore, yielding thirty-five per cent.
Localities.—Found in low, marshy grounds; widely distributed. Lebanon, N. H.; Berkshire and Plymouth Counties, Mass.; Columbia, St. Lawrence, Franklin and Jefferson Counties, N. Y.; New Limerick, Katahdin, Newfield, Shapleigh, Argyle, Clinton, Williamsburg and Lebanon, Me.; Darien and Martin Counties, Ind.; Monmouth County, N. J.; Somerset and Worcester Counties, Md.; Michigan, Ohio, Illinois, Wisconsin, etc.
13.—Brittle Silver Ore.
Occurs in crystals and masses; metallic lustre; tarnishes yellow, gray and finally black; easily cut or broken; when heated gives off fumes of sulphur and antimony, affording a button of silver; dissolved in nitric acid, it silvers copper placed in it; gravity 6.
Value.—A rich ore of silver, containing over sixty per cent.
Localities.—Found in veins with other silver ores, in Nevada and Idaho.
14.—Brown Coal.
Occurs like Bituminous Coal, but usually brownish-black with less lustre, and often showing a woody or slaty structure; powder always brown; contains fossil plants; gravity between 1.2 and 1.5.
Value.—Inferior to No. 10. Makes no coke. Can be used in the manufacture of alum.