236 PHYSIOGRAPHY. 



Tin-Ore Tin-Pyrites. 



denite. It occurs in pebbles and is extracted, in this shape from stream- 

 works, The variety wood-tin has only been met with in these reposito- 

 ries. 



5. Its principal deposits are in Saxony, Cornwall and Bohemia. It is 

 found in considerable abundance, both on the Bohemian and Saxon sides 

 of the Erzgebirge, disseminated in granite and in beds alternating with 

 it ; particular localities in this region, are Schlaggenwald, Altenberg, 

 Gezer, Ehrenfi iedersdorf, M;rienberg. Twin-crystals abound at Schlag- 

 genwald. In Cornwall, it exists in veins traversing granite and schist, 

 and is accompanied by green Talc, (var. Chlorite,) Fluor, Quartz, To- 

 paz, Tourmaline, Mispickel, Wolfram and Blende. At St. Michael's 

 Mount, it is disseminated through granite. The ore is chiefly in the 

 state of single crystals. Stream-works exist both in Cornwall and Saxo- 

 ny. It is found in Galicia, Spain, in mica-slate, in the granite hill of 

 Puy des Vignes, Haute Vienne, in France, and in the mountain chains 

 of Fichtel and RiesengebQrge in Germany. Other localities are in Asia, 

 on the east coast of Sumatra, Siarn and Pegu ; also at Banca and Malac- 

 ca, and in Mexico and Chili. A few black crystals have been found 

 with Tourmaline in Albite, at Goshen, (Mass.) 



TIN-PYRITES. Hexahedral Copper-Glance. 



Primary form. Cube. 



Massive : composition granular, strongly coherent. Frac- 

 ture uneven, imperfectly conchoidal. 



Lustre metallic. Color steel-grey, inclining to yellow. 

 Streak black. Opake. 



Brittle. Hardness =4'0. Sp. gr. =4-479 . . .4-515. 



1. Heated in an open tube, it gives the smell of sulphurous acid. 

 On charcoal before the blow-pipe, it melts, depositing at the same time 

 a white powder, which U not volatile and consists of oxide of tin, a brit- 

 tle globule remaining behind. On moistening the mass with muriatic 

 acid, and exposing it to the flame of a lamp, it colors it of a beautiful 

 blue. The mineral being treated with fluxes, gives the reactions of 

 copper and iron. It is soluble in nitro- muriatic acid, during which the 

 sulphur is precipitated. 2. Analysis. 



By KJ.APROTH. 



Sulphur . . . 2085 . . . 3500 

 Tin 38- 1 i 3400 



Copper . . . 41 04 . . . 39 00 

 Iron . . . 000 . . . 2-00 



