COLUMNAR DOLOMITE. 97 Third Subspecies. Columnar Dolomite. tv Stanglicher Dolomit, Klaproth. Stanglicher Dolomit, Klaproth, Mag. der Gesellsch. Naturf. Freunde, b. v. s. 402. External Charactersi Its colour is pale greyish-white. It occurs massive, generally in pieces about two inches long, which are covered with an isabella-yellow small botryoidal crust, and interwoven with greyish-white straigiit fibres of asbestus. The lustre is vitreous, inclining to pearly. The longitudinal fracture is narrow radiated, with de licate cross rents; the cross fracture is uneven, but spe cular in the cross rents; It occurs in distinct concretions* which are thin, long, and straight prismatic. It breaks into acicular-shaped fragments. It is feebly translucent. It is brittle. Specific gravity, 2.765, Constituent Paris. From the Mine Tschistagowekoy. Lime, - 28.20 Magnesia,- 19.74 Oxide of Iron, 0.50 Carbonic Acid, 39.25 Water, , - 11.31 Loss, i 1.00 Klaproth, Magaz. der Gesellch. Naturf. Freunde, t. v. s. 402. & 403. G Geognostie
