242 Elements of Mineralogy* 



SPECIES II. 



Mineralized By 'Sulphur. 



Vitreous Silver Ore, Glafzertz. 



6. It is found either in folid large lumps* 

 or inhering in quartz, fpar, gypfum, gneifs> 

 pyrites, &c. of a lamellar, granular or capil- 

 lary form, or cryftalized ; it is generally of a 

 lead colour firft, but grows black by expo- 

 fure to the air, but fornetimes grey or black, 

 even when firft broken; its laminae are 

 flexible and du&il, and even malleable in 

 fome degree, and fo foft, that they may be 

 cut with a knife; its fpecific gravity is 

 7,200 * ; it is one of the richeft of the filver 

 ores. 



100 parts of it contain from 72 to 77 of 

 filver ; it is rarely contaminated with any 

 other metal befides a fmall proportion of iron. 



7. It is found in Hungary near Sbemnitz, 

 and in Saxony near Freyburgh> particularly in 

 the fampus mine of Himmelsfurjt. 



8. It is analyfed by boiling it in moderately 

 dilute nitrous acid, ufing abou* 25 times its 

 weight, until the fulphur is quite exhaufted. 



* GeJlert Anfangs. 234. 



