a New Mineral Sjjecies. S43 



upon the remaining faces, which are deeply streaked parallel 

 to their intersections with a. 



Lustre metallic. Colour dark pinchbeck-brown, rather dark- 

 er than the colour of magnetic pyrites. Streak black. Tarnish* 

 often violet-blue on all the faces except a. - Kj-n 



Very sectile. Thin laminae perfectly flexible. Hardness 

 — 1.0... 1.5, little superior to talc. Specific gravity = 4.215. 



Compound varieties. Twin-crystals, joined parallel to a 

 face of P -f- 00, similar Fig. 3. Generally several crystals are 

 joined in an irregular manner, and implanted together, being 

 fixed to their support with one of fheir sides, so as to produce 

 rose-like aggregations and globules, with a drusy surface. Mas- 

 sive varieties usually present the aspect of a coarse-grained 

 mica. 



II. Observations. 



1. The two specimens from which the preceding descrip- 

 tion is drawn up I first saw when in Prague in March 1826. 

 They were pointed out to me as something not agreeing in se- 

 veral respects with the known species, by Professor Zippe, one 

 of them in the collection of the National Museum, the other in 

 the collection of Gubernialrath Neumann ; the latter speci- 

 men was designated on the ticket as a pinchbeck-brown proble- 

 matical fossil, crystallized in six-sided tables. Both these gen- 

 tlemen entrusted me liberally with the specimens for examina- 

 tion, the only specimens then known to exist. 1 am happy to 

 learn that Mr Zippe has succeeded in finding out a few more 

 specimens, in rummaging over some old store of minerals. 



2. There exists a considerable deal of resemblance, as ap- 

 pears also from the characters given, between the Sternbergite, 

 and the black tellurium, the flexible sulpharet of silver, and 

 the rhombohedral molybdena-glance. As a species it is suffi- 

 ciently distinct from all of them. On account of that resem- 

 blance it must receive its place in the order Glance of the system 

 of Mohs ; but whether as a genus of its own, or along with 

 some one or the other of those enumerated, is as yet uncertain, 

 while these species themselves are so imperfectly known. No 

 systematic denomination can therefore be at present proposed 

 for the new species. The name of Sternbergite, in proposing 



