in chemistry, a genus of fossils, of the order of the asphurelata: it is a dense, compact, and ponderous mineral, very bright and shining, and much resembling some of the antimonial ores. See ANTIMONY, and Chemistry, p. 139, 140, 141.

It is sometimes found of a deep blueish-black, very heavy and hard, and of a granulated structure, looking like a piece of pure iron where fresh broken: at other times it is found more compact, not granulated, but resembling a mass of melted lead on the surface. These are the more ordinary appearances of cobalt, besides which there are other accidental varieties of it, being sometimes found of a florid red; or a red defaced by mixtures of grey, black, or yellow; and in this state, it either forms an uniform mass, or a beautifully striated and ridged one.

From this mineral are produced the several kinds of arsenic, zaffre, and smalt. See Chemistry, p. 145.