TIN-WHITE COBALT-ORE. 495 , ORDER XVI.—COBALT. This Order contains eight species, viz. Tin-white Co- halt.ore, Grey Cobalt ore, Silver-white Cobalt ore, Co- halt-pyrites, Black Cobalt ochre, Brown Cobalt-ochre, Yellow Cobalt-ochre, and Red Cobalt-ochre. 1. Tin-white Cobalt-Ore. Weisser Speisskobald, Werner. Weisserspeisskobalt, Lud. b. i. s. 283. Id. Mohs, b. iii. s. 647. Id. Leonhard, Tabel. s. 76. Id. Karsten, Tabel. s. 72—Speiss- kobalt, Hutis. s. 75. (in part).—Cobalt arsenical, var. Blanc ar gentine, Haui/, Tabl. p. 107-—Arsenical Cobalt, Aikin, p. 59- (in part.) / External Characters. On the fresh fracture its colour is tin white ; but it tar nishes grey or blackish, rarely reddish or yellowish, and sometimes variegated. „ it occurs massive, disseminated, in membranes, specu- hm, globular, botryoidal, thin cylindrical, frequently reti- oulated, fruticosc; and crystallised in the following fi gures : 1. Cube, in which the faces are sometimes spherical convex; and (lie edges and angles are sometimes more or less deeply truncated. This figure is frequently cracked or burst in determinate direc tions.