BROCHANTITE, a mineral species consisting of a basic copper sulphate crystallizing in the orthorhombic system. The crystals are usually small and are prismatic or acicular in habit ; they have a perfect cleavage in one direction. They are transparent to translucent, with a vitreous lustre; and are of an emerald-green to blackish-green colour. Specific gravity hardness The mineral has been found associated with malachite, etc., in copper mines at several places. A micro scopical examination of the green copper ores of secondary origin in the Clifton and Morenci district of Arizona proves brochantite to be of extremely common occurrence mostly intergrown with malachite, which effectually masks its presence. (L. J. S.)