45 PHYSIOGRAPHY. , CLASS if. 



silver, lead, and tin, by several species of the order Pyri- 

 tes, very frequently by rhombohedral Quartz, and it is 

 scarcely ever found without dodecahedral Garnet-blende. 



4. Prismatic Arsenical-pyrites is plentiful in several of 

 the mining districts of Saxony ; it is found in beds at 

 Breitenbrunn and Raschau, in veins at Freiberg, Munzig, 

 &c., also in the tin-veins and beds of Altenberg, Geyer, 

 Ehrenfriedersdorf, and other places. In Bohemia it is 

 found in the silver mines of Joachimsthal and the tin mines 

 of Schlaggenwald. Reichenstein and Kupferberg in Sile- 

 sia, which are quoted as localities, are rather doubtful, 

 no attention having hitherto been paid to the difference 

 between the two species of prismatic and axotomous Arse- 

 nical pyrites. It occurs at Andreasberg in the Hartz, 

 at Tunaberg in Sweden, at Wheal Maudlin and other 

 mines in Cornwall, and in many other countries. The 

 argentiferous variety is principally found at Braunsdorf 

 near Freiberg, in quartzy veins in mica-slate. A variety 

 in small acicular crystals, much resembling the preced- 

 ing one, but containing no silver, is found in sandstone, 

 in a place called Braza, near Zalathna in Transylvania. 



5. The accidental admixture of silver renders some va- 

 rieties of the present species useful as ores of that metal. 

 The common Arsenical pyrites is employed in the manu- 

 facture of white arsenic and of realgar. Sometimes it con- 

 tains a small proportion of gold. 



GENUS III. COBALT- PYRITES. 

 1. OCTAHEDRAL COBALT-PYRITES. 



Octahedral Cobalt-Pyrites. JAM. Syst. Vol. III. p. 282. 

 Octahedral Cobalt-Pyrites or Tin-White Cobalt. Man. 

 p. 269. Bright White Cobalt. PHILL. p. 270. Weisser 

 Speiskobold. WERN. Hoffm. H. B. IV. 1. S. 173. 

 Speiskobalt. HAUSM. I. S. 155. Speiskobalt. LEONH. 

 S. 299. Cobalt arsenical. HAU Y. Traite, T. IV. p. 200. 

 Tabl. comp. p. 106. (excepting C. a. gris-nomltre). 

 ^, 2de Ed. T. IV. p. 2 1 9. (with .the same exceptions). 



