238 PHYSIOGRAPHY. 



Grey Antimony. 



Cleavage, highly perfect in the direction of A, or the 

 shorter diagonal of the prism ; much less distinct parallel 

 with M. Fracture small conchoidal, rather imperfect. 

 Surface, the vertical planes deeply striated parallel to their 

 own intersections, and rough. The remaining faces gene- 

 rally smooth. Subject to tarnish. 



Lustre metallic. Color lead-grey, inclining to steel- 

 grey. Streak unchanged. 



Sectile. Thin laminae are a little flexible. Crystals 

 sometimes bent. Hardness =2-0. Sp. gr. =4-62. 



Compound Varieties. Massive ; composition colum- 

 nar, of various sizes of individuals, sometimes very thin, but 

 not impalpable. They are long and straight, either paral- 

 lel or divergent from several common centres, and aggrega- 

 ted in a second angulo-granular composition. The faces 

 of composition are irregularly streaked in a longitudinal di- 

 rection. Sometimes the composition is granular, and then 

 the individuals often become impalpable, but are generally 

 very strongly connected ; the fracture becomes even or un- 

 even. Capillary crystals often form a tissue resembling 

 wool, or felt, 



1. Grey Antimony is very fusible before the blow-pipe, and is absorb" 

 ed by the charcoal. By a continued blast, it may be valatilized, with- 

 out leaving any considerable residue. 



2. Analysis. 



By PROUST. By THOMSOX. 



Antimony - - 75-00 - - 73-77 



Sulphur - - 25-00 - 26-23 



3. The present species occurs in veins and beds : in the latter case 

 along with Spathic Iron. It is frequently associated with Heavy- Spar, 

 Blende and Quartz. Its decomposition produces the Antimony- Ochre, 

 a friable, compact yellow substance, with which it is often associated or 

 covered. 



