ORDER xi. PRISMATTC TELLURIUM-GLANCE. 17 



Combinations. 1. P oo. P -f cc. ?r -f- oo. 

 2. P oo. P -f- x. ?r H- oo. Pr -f oo. Nagyag, 

 Transylvania. 



Cleavage, P oo, very perfect. Fracture not ob- 

 servable. Surface, P oo smooth. 



Lustre metallic. Colour blackish lead-grey. Streak 

 unchanged. 



Highly flexible in thin laminae. Very sectile. 

 Hardness = 1-0 ... 1-5. Sp. Gr. = 7-085. 



Compound Varieties. Massive : composition 

 granular, of various sizes of individuals, sometimes 



longish. 



OBSERVATION'S. 



1. According to KLAPROTH, the prismatic Tellurium- 

 glance consists of 



Tellurium 32-20. 



Lead 54-00. 



Gold 9-00. 



Silver 0-50. 



Copper 1-30. 



Sulphur 3-00. 



Before the blowpipe it melts easily upon charcoal, emits 

 white fumes, which are deposited upon the charcoal, and 

 gives a malleable metallic globule. "NVith borax it gives a 

 bead of gold containing a little silver. It is easily soluble 

 in nitric acid. 



2. It has been hitherto found only in veins with hexa- 

 hedral Gold, hexahedral Glance-blende, dodecahedral Gar- 

 net-blende, macrotypous Parachrose-baryte, &c. 



3. Its chief locality is Nagyag in Transylvania, from 

 whence it obtained its ancient name of Nglakcr-Erz. It 

 is found also with prismatic Antimony-glance, at Offen- 

 banya in the same country. 



VOL. III. B 



