ORDER X. HEXAHEDRAL IRON-PYRITES. 457 



upon charcoal a large quantity of arsenical fumes, and 

 melts only after having been roasted. It imparts a blue 

 colour to borax and other fluxes, and is acted upon by nitric 

 acid, like the preceding species. 



2. Hexahedral Cobalt-pyrites occurs in beds in primitive 

 rocks and in veins. It is accompanied chiefly by Iron- 

 pyrites, Arsenical-pyrites, and Copper-pyrites ; in beds it is 

 also associated with octahedral Iron-ore, and several species 

 of the genera Augite-spar, Feld-spar, &c. ; in veins it is 

 sometimes found with several species of Haloide and Baryte. 

 The crystals found in beds are terminated from all sides, 

 and are the finest varieties of the species. 



3. The hexahedral Cobalt-pyrites occurs in the parish of 

 Modum in Norway, at Tunaberg in Sudermanland in Swe- 

 den, at Querbach in Silesia, and Bottallack near St Just in 

 Cornwall. It is found also in several of the mines in the 

 district of Siegen. 



4. It is highly valued as an ore of cobalt, for painting 

 jon porcelain, and manufacturing smalt. 



GENUS IV. IRON-PYRITES. 

 1. HEXAHEDEAL IRON-PYRITES. 



Hexahedral Iron- Pyrites or Common Iron-Pyrites. JAM. 

 Syst. Vol. III. p. 291. Hexahedral Iron-Pyrites. 

 Man. p. 271. Iron pyrites (in part). PHILL. p. 217. 

 Gemeiner Schwefelkies. Zelkies (in part). WERN. 

 Hoff'm. H. B. III. 2. S. 191. 205. Schwefelkies. 

 HAUSM. I.S. 147. Eisenkies. LEONH. S. 324. Fer 

 sulfure (in part). HAUY. Traite', T. IV. p. 65. Fer 

 sulfure (in part). Tabl. comp. p. C9. Traite', 2de Ed. 

 T. IV. p. 38. 



Fundamental form. Hexahedron. Vol. I. Fig. 1. 

 Simple forms. H. (P, M), Val di Brozzo, Pied. 



mont ; 6 (d), Vol. I. Fig. 2., Akudlek, Green- 



* 



land; D, Vol. I. Fig. 31.; ~ (y), Stiria ; ~ 



