PHYSIOGRAPHY. 



Lazulite. 



Secondary form. Fig. 273. 



158 10' 

 120 40 

 00 

 36 

 25 



150 

 162 

 139 

 141 



20 



Fracture uneven. 



MonM 



M on e 

 M and 

 MOD/ 

 a on a 

 a on cl 



Cleavage, parallel with a indistinct. 

 Surface smooth, all the faces alike. 



Lustre vitreous. .Color various shades of a pure blue 

 color, particularly deep and beautiful if viewed in the direc- 

 tion of one line, apparently the axis of the crystals ; while 

 perpendicular to it, it is of a pale greenish blue color. 

 Streak white. Translucent, generally only on the edges, 

 opake. 



Brittle. Hardness = 5-0 ... 5-5. Sp. gr. = 3-056. 



Compound Varieties. Massive : composition granular, 

 individuals strongly connected. 



1. Before the blow-pipe, it intumesces a little, and assumes a glassy 

 appearance, where the heat has been highest, but does not melt. With 

 borax, it yields a clear colorless globule. Treated with boracic acid and 

 a piece of iron-wire, it gives a globule of phosphuret of iron. 

 2. Analysis. 

 By FTJCHS. 



h These planes may be taken also as the primary planes. 



i* 



