44 PHYSIOGRAPHY. 



Atmospheric-air. 



The planes M M' are the result of cleavage. Among the minute crys- 

 tals are to be observed some in which the planes 2, 2> and c, c f of fig. 

 48 prevail to the exclusion of the rest, converting them to the form of an 

 octahedron with a square base. 



Cleavage parallel to P, less distinct parallel to M and M 7 . 



Colors, olive, leek, grass, emerald, and blackish-green. 

 Streak apple-green. Nearly transparent . . . translucent on 

 the edges. 



Rather brittle. Hardness = 3-0 . . . 3*5. Sp. gr. = 



4-43. 







1. It communicates bright blue and green colors to the flame of a can- 

 dle, or if exposed to the blast of the blow-pipe, it develops vapors of mu- 

 riatic acid, and melts at last into a globule of copper. It is soluble with- 

 out effervescence in nitric acid. 



3. It is found at Remolinos in Chili, on Brown Iron-Ore; sometimes 

 with Red Oxide of Copper and Malachite: it occurs also in Peru with some 

 of the ores of silver. It is found in the form of fine sand in the river Li- 

 pas, in the desert of Atacarna, (and hence the name of the species,) sepa- 

 rating Chili from Peru. Other localities are, Schwarzenberg in Saxony, 

 and Mount Vesuvius. 



ATELESTITE. 



Crystalline, in structure resembling Sphene. 



Lustre resinous to adamantine. Color pure sulphur-yellow. 



Transparent to translucent. 



Hardness about 3. Heavy. 



1. Before the blow-pipe, it affords the indications of bismuth. 



2. It is found at Schneeberg. 



ATMOSPHERIC-AIR. Pure Atmospheric-gas. 

 MOHS. 



