PHYSIOGRAPHY. 



Leucopyrite. 



Secondary form. 



Fig. 277. 



M 



M 



Stiria Bedford co. (Penn.) 



o on o - 

 M on o - 



51 30' 

 about 146 00 



Cleavage, perfect parallel to the longer diagonal ; less 

 distinct parallel with two faces on the acute lateral edges, 

 inclining under 86 10'; traces parallel with M. Frac- 

 ture uneven. Surface faintly streaked, parallel to the com- 

 mon edges of combination, frequently smooth. 



Lustre metallic. Color between silver-white and steel- 

 grey. Streak greyish-black. 



Brittle. Hardness = 5-0 ... 5-5. Sp. gr. = 7-228, 

 from Silesia ; 7-337, crystal from Bedford co. (Penn.) 



Compound Varieties. Massive : composition granular, 

 individuals small, often nearly impalpable, and strongly con- 

 nected ; fracture uneven ; composition columnar, rather 

 thick, irregular, and divergent. Faces of composition 

 irregularly streaked. 



1. It is sometimes magnetic even with polarity. It melts before the 

 blow-pipe, without giving any perceptible smell of arsenic ; but when 

 fused in quantity beneath the flame of the compound blow-pipe, the odor 

 of arsenic is perceptible. It is perfectly soluble in nitric acid, a few 

 flakes of Plumbago, only, remaining undissolved in the solution. 



