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asiaasei 6'S CHRYSOLITE FAMILY. 5. Less oblique four-sided prism, in which the obtuse edges are truncated, the acute bevelled, and the bevelment truncated; acuminated on the extre mities with eight planes, of which four are set obliquely on the lateral planes of the prism, four straight on the truncated lateral edges. The apex of the acumination truncated *, fig. 123. 6. N° 3. in which the lateral edges, in place of being truncated, are bevelled-f - , fig- 124. Some crystals are very thin and reed-like, or table shaped. The crystals are middle-sized and small, and appear to have been imbedded. The broader lateral planes in all the varieties, with ex ception of N° 4., are deeply longitudinally streaked; but the smaller lateral planes are often smooth, and the acu minating planes always smooth. Internally the lustre is splendent and vitreous. The fracture is perfect flat conchoidal. The fragments are very sharp-edged. It is transparent, and refracts double, particularly when viewed through the broader acuminating planes, and the obliquely opposite broader lateral planes ol N° 1. It is hard, but in a low degree; scratches glass and felspar, but is scratched by quartz and tourmaline. It is brittle. It is easily frangible. Specific gravity, 3.340, 3.420, Werner. 3.428, Hauy, 3.301, 3.472, Kartlen. 3.343, Lowry. Chemical * Peridot doublSnt, Hauy. f Peridot quadrnplant, Hauy.
