MINERALS AND GEOLOGY OF CANADA. 527 
masses) = 124°30! in hornblende, and 87°85’ in augite ; 
but some of the lightcoloured (dzopside) crystals belong- 
ing to the latter, occur in flat rhombic prisms like fig. 40 
above, and give an angle of 141°21'*. Structure, 
Jamellar or fibrous. H.5-0-6-0; sp. gr. 8:2-3:5. Fu- 
sible, the dark varieties yielding magnetic globules. 
Composition, as in Hornblende: see above. The dark- ewan 
green, black, and brown varieties commonly bear the name of 
augite (proper) or pyroxene; the clear green varieties, that of 
sahlite; and the white, greyish, or pale-green varieties, that of 
diopside—but many additional names have been bestowed on this 
mineral, in relation to. locality, structure and other conditions. Both 
hornblende and augite, it should be remarked, offer a transition to 
serpentine: one stage in this transition producing the peculiar 
varieties, asbestus and amianthus. These are chiefly of a light-green 
or white colour, fibrous, silky, and flexible—often to such an extent as 
to admit of being woven into cloth. Dvrallaye, described below, 
appears to be a transitional form of this kind. Augite occurs in 
the bands of crystalline limestone—and in some places as a rock 
component, forming, in admixture with Wellastonite, distinct beds— 
‘interstratified with the gneissoid rocks of the Laurentian Series, as 
in the counties of Argenteuil, Terrebonne, &. In Argenteuil county, 
a green, granular variety (Coccolite) is also found. This mineral 
oceurs likewise in the metamurphie schists of the eastern townships, 
and in crystals and granular masses in the eruptive rocks of 
Montarville, Rougemont, &c., belonging to that section of the 
Province. 
Hypersthene. Bronzite. Diallage—These are generally regarded 
as varieties of Augite. They occur in cleavabie masses of a pinch- 
beck-brown, green or greenish-grey colour, usually with a pseudo- 
metallic lustre. Sp. gr. 3:2-3°5. Fusible more or less readily, the 
dark varieties yielding a magnetic bead. Dtallage is of low hardness, 
and it yields almost always a little water in the bulb-tube, and hence 
will be referred to amongst the minerals of D 4 and D 5 below. In 
composition, these minerals, like augite, are essentially silicates of 
magnesia (or of magnesia and protoxide of iron.) Hypersthene 
* If we denote the first prism in augite by V, this latter prism = V3. Itis the most 
common form of the diopside prisms imbedded in our crystalline limestone, 
