36 PHYSIOGRAPHY. CLASS II. 



GENUS III. PURPLE-BLENDE. 



I. PRISMATIC PURPLE-BLENDE. 



Prismatic Antimony-Blende or Red Antimony. JAM. 

 Syst. Vol. III. p. 421. Man. p. 290. Red Antimony. 

 PHILL. p. 331. Rothspiesglaserz. WERN. Hoffm. 

 H. B. IV. 1. S. 114. Rothspiessglanzerz. HAUSM. I. 

 S. 225. Antimonblende. LEONH. S. 157. Antimoine 

 hydro-sulfure'. HAUY. Traite', T. IV. p. 276. Anti- 

 moine oxyde' sulfure'. Tabl. comp. p. 1 13. Traite', 2de Ed. 

 T. IV. p. 311. 



Fundamental form. Scalene four-sided pyramid. 

 Inclination of the axis = 11 19' in the plane of 

 the long diagonal. Vol. I. Fig. 41. AP. 



a : b : c : d = 5-0 : 3-1 : c : 1. 



Simple forms. P oo ; -^- = 15 47' ; y 

 = 34 & ; Pr -f oo. The faces of all the forms 

 hitherto observed, are parallel to one of the dia- 

 gonals of P, and this is supposed to be the short 

 diagonal. 



Char, of Comb. Hemi-prismatic. Inclination of 

 P oo on r + OD - 101 1^. 



Combinations. 1. y- f r + oo. 2. P oo. 



_ fr+o. 3.P-OC. *L -*. 



fr + oo. All of them are elongated, and often 

 appear only as thin filaments parallel to the short 

 diagonal ; the termination of the crystals in that 

 direction has not been observed. 

 Cleavage, fr + QD highly perfect; less distinct 

 Pr -f oo ; there are traces in other directions 

 perhaps of P -f- QD. Fracture not observable. 



