PHYSIOGRAPHY. 



Pharmacolite. 



101 



1. Before the blow-pipe, it fuses with greater difficulty than Feldspar. 



2. Analysis. 



By BERTHIER. 



3. Petrosilex is probably a variety of Feldspar, or Albite. 



PHARMACOLITE. Hem i-prismatic Gypsum- 

 Mica. 



Primary form. Right oblique angled prism. 

 Secondary forms. 



Fig. 334. Fig. 335. 



/on/ 

 n on n 



117 24' HAIDINGER. 

 141 8 " 



The crystals are lengthened in the direction of T, (edges 

 of combination between T, n and P,) and attached at one 

 of the extremities, in most cases several together, so as to 

 form stellated or divergent groups. On the disengaged ter- 

 minations of the crystals, one of the faces/ is enlarged, so 

 as generally to make the other disappear. 



