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2 DIAMOND FAMILY. ish-Tvhite, and yellowish-white; of grey, ash-grey, smoke- grey, bluish-grey, pearl-grey, yellowish and greenish, grey. Besides these two colours, it occurs blue, red, brown, yellow, and green. Of blue, the only variety is indigo-blue, which appears, to pass into red. Of red, the varieties are rose-red and cherry-red; from the latter it passes into clove-brown and yellowish-brown; from this into ochre-yellow, orange-yellow, wine-yellow, lemon and sulphur yellow; further, into siskin green, asparagus-green, pistachio-green, leek-green, and, lastly, into mountain-green: which latter passes into greenish- grey, and greenish-white. The clove-brown passes into blackish-brown, pitch- black, and greyish-black *. Of all the colours, blue and black are the rarest. The colours are generally pale and light, seldom deep, and very seldom dark. It exhibits a most beautiful play of colours, in the direct rays of the sun, or in candle light, particularly when cut. It occurs in rolled pieces, in indeterminate and sphe rical grains; also crystallised in the following figures; 1. Perfect equiangular octahedron, or double four sided pyramid, in which the lateral planes are sometimes straight, sometimes convex -f\ This is the fundamental figure, or that from which all the others are supposed to Ije derived. Plate I. fig. 1. 2. Octahedron, with alternate larger and smaller planes. 3. Te- * Mohs, in his Description of Von dor Null’s cabinet, mentions a e TC J“ ish-black diamond. ■f Diamant primitif, Haay.