TIM: NATIVE ELEME1 293 



States is '.) parts ^t>ld to 1 of copper, or ( .K)() line. The proportion 

 in je\velry i designated by th;- carat, 121 carat being pun- Hold. In 

 Kniiland the usual standard is 22 carat, or ( .H<.r>7 fine. 



MERCURY 



Mercury. Quicksilver, Hg; Isometric; Type, Dites.-eral Cen- 

 tral; Crystals, octahedrons: Liquid at ordinary temperature.-: 

 Solid at 39 with cubic cleavage ; G. = 13.6; Color, tin-white; 

 Brilliant metallic luster; Opaque. 



B.B. Volatilizes entirely when pure, yielding a gray coat on 

 coal. See tests on page 579. 



General description. Native mercury is not of common occur- 

 rence. It is found as small metallic liquid globules in the gangue 

 associated with cinnabar, from which it has probably been reduced 

 by organic agents. It also occurs in shales, slate, and marls, as at 

 Idria, Austria, one of the important European localities, where it 

 occurs in a clay slate. The deposits of California and Texas where 

 native mercury is found are also associated with sedimentary 

 rocks, which yield hydrocarbon gases. Hot springs, as the Steam- 

 boat Springs of Nevada, bring mercury to the surface. 



The mercury of commerce is obtained from the sulphide, cinna- 

 bar. In the United States, California for a long time was the only 

 producing state, but since the discovery of the mercury deposit- at 

 Terlingua, Brewster County, Texas has also been a producer. 

 About twenty-one thousand flasks, of seventy-five pounds each, 

 were produced in the United States in 1911, of which California 

 produced seventeen thousand. 



The greatest demand for mercury is in the amalgamation of silver 

 and gold ores. It is also used in the production of vermilion paint, 

 and in smaller quantities in the sciences and in the construction of 

 electrical apparatus. 



The metals iron, lead, bismuth, arsenic, and antimony are also 

 found in nature in a free state, but only locally and in very restricted 

 quantities. Iron occurs in meteors and as a primary accessory com- 

 ponent in some basalts, as at Antrim, Ireland, in the trap of New 

 Jersey, and in the dolerites of Mount Washington, New Hampshire. 

 The most noted locality, however, is at Disco Island, West Green- 

 land, where large masses, many tons in weight, have weathered out 

 of the basalt ; these masses were originally supposed to be meteoric. 



