442 DESCRIPTIVE MINERALOGY. 



ORDER XL SILVER. 



1. Native Silver. 2. Vitreous Silver. 



NATIVE SILVER. 



Argent Natif. Bauy and Bevdant. — Native Silver. Cleaveland, Phillips, ThomKm and Shepard. — Hez&hedral 

 Silver. Jamescm. — Hexaedrisches Silber. Mohs. 



Description. Colour silver-white, but usually more or less tarnished externally. Streak 

 shining. It occurs regularly crystallized ; also massive, disseminated, capillary, branching 

 and reticulated. The primary form is thought to be a cube, but it is also found in the form 

 of a regular octahedron. Cleavage none. Fracture hackly. Lustre metallic. Opaque, 

 Flexible, ductile and malleable. Hardness from 2.5 to 3.0. Specific gravity 10.74. Fusi- 

 ble by the blowpipe into a globule, which is not altered by continuing the heat, although on 

 cooling it exhibits faces of the cube, the octahedron and dodecahedron. It is soluble in nitric 

 acid, and the solution gives a white precipitate on the addition of common salt, which, on 

 exposure to the light, assumes a purple colour. 



Native silver is sometimes associated with gold, when it is known by the name of Aurife- 

 rous Native Silver. A variety of this gave Klaproth, silver 34.00, gold 64.00 ; but these 

 proportions are subject to great variation. 



Geological Situation. Native silver generally occurs in veins of calcareous spar or 

 quartz, traversing gneiss, slate, and other primitive rocks, occasionally also in selenite and 

 clay. The most remarkable localities are the mines of Konsberg in Norway, which formerly 

 afforded magnificent specimens ; and those of Peru and Mexico in South America. 



localities. 



Cleaveland enumerates several localities of native silver in the northern States. Among 

 these is one at Sing-Sing in Westchester county, New-York, first noticed by Col. Gibbs ; 

 another in New-Jersey ; and still another, at Huntington in Connecticut. 



The occurrence of native silver in this State, although doubted, has been confirmed by 

 Dr. Torrey, who informs us, that in 1825, Mr. F. Cozzens obtained a specimen from the 

 mine about a mile south of the Sing-Sing prison.* This mine was wrought for silver, during 

 the American revolution, but probably with little success. In 1827, a company was formed 

 for the purpose of working it. The old shaft was cleared out, and an adit or level commenced. 

 A small quantity of ore, principally galena, was obtained, and the work was then abandoned. 

 Native silver has recently been found at King's mine in Davidson county, North Carolinat ; 



* AnnaU of the Lyaum of Natural Hittory of New-York. IV. 76. t Prof. J. C. Booth. American Jomnal of Saaut. 'S.hl. 3iS- 





