34-G PHYSIOGRAPHY. CLASS II. 



Cleavage, Pr -f- GO, pretty easily obtained, some- 

 times traces of Pr -f- GO. Fracture conchoidal. 

 Surface, P GO generally rough, so is also 

 Pr -f- GO. The faces of the vertical prisms streak- 

 ed parallel to the axis, those of the rest of the 

 faces smooth and even. The grains possess an 

 uneven surface. 



Lustre vilreous. Colour various shades of green, 

 as pistachio-green, olive-green, nearly asparagus- 

 green and grass-green, sometimes passing into 

 brown. Streak white. Transparent ... trans- 

 lucent. 



Hardness = 6-5 ... 7'0. Sp. Gr. = 3441, acrys- 

 tallized variety. 



Compound Varieties. Irregular spheroidal mass- 

 es, imbedded in rocks : composition granular, in- 

 dividuals easily separated, faces of composition un- 

 even and rough. 



OBSERVATIONS. 



1. The two species, Chrysolite and Olivine, generally dis- 

 tinguished among the varieties of the present species, do 

 not yield any decisive character by which they might be 

 separated. Chrysolite are called the varieties in perfect 

 crystals, or such varieties as possess bright colours and 

 pretty high degrees of transparency. Yet there are some 

 crystals and imbedded grains by no means inferior to them, 

 which are exhibited among the varieties of Olivine, which, 

 for the greater part, however, contain only compound va- 

 rieties of inferior degrees of transparency, and less li vely co- 

 lours. The varieties found in the meteoric iron discovered 

 by PALLAS in Siberia, in fact belong to the present species, 

 as not only their forms, but also the rest of their properties, 

 agree with those enumerated above. 



