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70 CHRYSOLITE FAMILY. Observations. 1. This mineral is characterised by its pistachio-green colour, the other varieties occurring rarely; the fine splin tery or scaly surface of the angular pieces; its crystalli zations, internal lustre, fracture, inferior hardness, and weight. 2. Distinctive Characters.—a. Between Chrysolite and Vesuvian. If the vesuvian be in rolled pieces, it can be distinguished from chrysolite, by its wanting the fine scaly or splintery surface -which characterises that mine ral : if in crystals, by their being very slightly longitudi nally streaked, having a fine-grained uneven fracture, and resinous internal lustre; whereas the crystals of chrysolite are deeply longitudinally streaked, the fracture is conchoidal, and the lustre vitreous. A simple chemi cal distinctive character may be mentioned : vesuvian is fusible before the blowpipe, chrysolite is infusible.—b. Between Chrysolite and yellowish-brown and olive-green Tourmaline. Tourmaline becomes strongly electric by hedting, but the chrysolite only by rubbing ; tourmaline is harder than chrysolite, as it scratches glass more readily.—c. Between Chrysolite and Asparagus-stone of Werner. Asparagus-stone does not scratch glass so' easily as chrysolite, and refracts single, whereas chryso*- lite refracts double. 3. Werner is of opinion, that the stone described by the ancients, under the name Yellow Chrysolite, is not the true chrysolite, but our topaz. The celebrated truveller Bruce, mentions an Emerald Island in the Bed Sea; but says that the substance he there met with, was scarcely harder than glass. Dr Kid remarks, “ May not this have been a chrysolite, and this island the Topaz Island mentioned by Plinv ?” Home de Lisle and Born, de scribe