502 



schaller: minasragrite 



lar granular masses, indistinct short prisms, and rarely sharply 



defined units of a rhombic shape (angle about 78°). Some 



pieces break up into similar rhombs by cleavage, so that it 



may be that all the observed rhombs are cleavage pieces and 



not distinct crystals. From the general inclined extinction of 



all straight edges it is concluded that the mineral is monoclinic 



or triclinic. 



TABLE 1 



Analysis of Minasragrite Mixed with Impurities 



TABLE 2 

 Recalculated Analysis and Ratios of Minasragrite 



The color of minasragrite is blue, the luster vitreous. The 

 refractive indices are approximately as follows: a =1.515, 

 /3 = 1.525, 7 = 1.545. The pleochroism is strong: X = deep 

 blue, Y = blue, Z = colorless. The mineral is optically negative. 



Heated in a closed tube, minasragrite readily fuses and gives 

 off water. It is very soluble in cold water. The sample scraped 

 off for analysis necessarily contained all the minerals of the 

 efflorescence, which were separated from the patronite by cold 

 water. The water of the sample had to be expressed by differ- 



