6 Description of STERXBERGITE, 



The flexible sulphuret of silver was found by Dr WOLLASTON 

 to contain silver, sulphur, and some traces of iron. In this re- 

 spect Sternbergite is very nearly allied to it, only the iron forms 

 a much more considerable part of the composition, as appears from 

 the experiments with the blowpipe. 



In the glass-tube it gives off a strong odour of sulphurous 

 acid, loses its lustre, and becomes dark-grey and friable. Alone 

 on charcoal, it burns with a blue flame, and sulphurous odour, 

 and melts into a globule, generally hollow, with a crystalline sur- 

 face, and covered with metallic silver. The globule acts strong- 

 ly on the magnetic needle, and before the blowpipe it has all the 

 properties of sulphuret of iron. It communicates to fluxes the 

 ordinary colours produced by iron, red while hot, and yellow on 

 cooling, in the oxidating flame, greenish in the reducing flame. 

 Borax very readily takes away the iron, and leaves a button of 

 metallic silver. 



The characters observable in Sternbergite, and its great re- 

 semblance to the black tellurium, to the flexible sulphuret of sil- 

 ver, to the rhombohedral molybdena-glance, unequivocally as- 

 sign it a place in the order Glance of the system of Professor 

 MOHS. Whether it should form a genus of its own, or be com- 

 prised within one genus, with one or several of the above-men- 

 tioned species, remains doubtful, as long as those species them- 

 selves are so imperfectly described. No systematic name, there- 

 fore, can at present be applied to it. 



In proposing a single name for this mineral, I cannot find a 

 more appropriate one than that of Sternbergite, in honour of 

 Count CASPAR STERNBERG ; and I know, that, in doing this, I 

 concur with the feelings of my friends NEUMANN and ZIPPE, who 

 so liberally furnished me with the specimens examined. I could 

 not forego the pleasure of thus paying a just tribute to a man 

 in his exalted station in life, equally high in scientific attain- 



