286 
DESCRIPTIVE MINERALOGY. 
PYROXENE. 
[From the Greek tfup, fire , and gsvo?, a stranger; because it was found in lava, to which Haiiy consi¬ 
dered it as not belonging.] 
Augite. Cleaveland and Phillips. — Paratomous Augite. Jameson. — Paratomer Augit-Spath. Mohs. — Pyroxene. 
Shepard and Dana. 
It includes Augite, Diopside, Mussite, Sahlite, Fassaitc, Baikilite and Coccolite. Dr. Thomson makes a distinct spe¬ 
cies of White Augite, which includes Diopside, Mussite, Alalite, Sahlite and Malacolite. The rest are united under his 
Pyroxene. 
Beudant has a subgenus Pyroxene, under which he arranges as distinct species, Diopside, which includes the white 
and light green varieties; Hedenbcrgite, comprising those which are dark green and black; Pyrodmalite and Hyper- 
sthene. Between the two tirst it is, however, exceedingly difficult to draw the line of specific distinction. 
Description. Colour green, black and brown ; also grey and white. 
It occurs regularly crystallized ; also in grains, and amorphous. The 
primary form is an oblique rhombic prism. Fig. 192. M on M 7 87° 
5 7 ; M or M 7 on P 100° 10 7 or 100° 25 7 . Cleavage parallel with M 
rather perfect, but interrupted ; in some varieties, it is very perfect in 
the direction of P. Fracture conchoidal and uneven. Lustre varies 
from vitreous to resinous. Ranges from transparent to opaque. Hard¬ 
ness from 5.0 to 6.0. Specific gravity from 3.20 to 3.50. Before 
the blowpipe, it fuses, emits a few bubbles, and finally yields a glassy 
globule, more or less tinged by iron. It is readily soluble with borax. 
Several varieties of pyroxene have been obtained artificially by means 
of fusion. 
Pyroxene often resembles hornblende, but can be distinguished by the difference in its 
crystalline form, and in its behaviour before the blowpipe. 
Varieties. The following varieties of this mineral deserve to be particularly noticed : 
Diopside — White Augite — Mussite — Alalite. This variety is generally crystallized. 
The colour is white or pale green. Translucent or transparent. The primary is an oblique 
rhombic prism, of the same form and measurement as that of pyroxene. Before the blow¬ 
pipe, it fuses into a colourless semi-transparent mass; with borax, into a diaphanous glass. 
Pyrgom — Pyrogome — Fassaite. This is generally of a dingy green colour; assumes 
nearly the same crystalline form, and yields to mechanical division parallel to the lateral planes 
of a prism of the same measurements as that of pyroxene. 
Sahlite — Malacolite — Baikilite. It occurs in prismatic crystals of four or eight sides, 
with inclined summits. It is of a greenish grey colour. It often occurs massive. The 
structure is lamellar, and it has the same primary form as the preceding. 
Common Augite — Conchoidal Augite. This includes all the varieties in which the colours 
are dark green and black, with a conchoidal and uneven fracture, and a resinous lustre. It 
is opaque or faintly translucent on the edges. 
Fig. 192. 
