TIX-PYRJTES. 163 



Colour rose-red. Streak greyish-white. 

 Scratched by quartz, and yielding to the knife 

 with difficulty. 



This mineral is very imperfectly described, as all the 

 properties given do not suffice, if it be a particular species, 

 to distinguish it from the Manganese-spar, at least by cha- 

 racters derived from the descriptions of the two substances. 

 It occurs at Tellemarken in Norway with rhombohedral 

 Quartz, octahedral Fluor-haloide, and Cyprine, which is 

 said to be a cupriferous variety of pyramidal Garnet. 



TIN-PYRITES. 



GLANCE. 



Tin-Pyrites. JAM. Syst. Vol. III. p. 325. Man. p. 332. 

 Tin Pyrites. Sulphuret of Tin. PHILL. p. 254. 



Form probably tessular. Massive : composition 



granular, strongly coherent. Fracture uneven, 



imperfect conchoidal. 

 Lustre metallic. Colour steel-grey, inclining to 



yellow. Streak black. Opake. 

 Brittle. Hardness = 4-0. Sp. Gr. = 4-350, 



KLAPROTH. 



In the collections of Mr RASHLEIGH of Menabilly, and 

 Mr WILLIAMS of Scorrier, crystals of Tin-pyrites are 

 preserved, having apparently the form of regular hexahe- 

 drons, but their surface is dull. The traces of cleavage, 

 sometimes observed in massive varieties, seem likewise to 

 be parallel to this form, and at the same time parallel to 

 the dodecahedron. 



Before the blowpipe sulphur is driven off, and the mine- 

 ral melts into a blackish scoria, without yielding a metallic 

 button. It is soluble in nitre-muriatic acid, during which 



