BLACK-Wadd, an ore of manganese, of which, according to Klaproth, it contains 68 per cent. It is of a brown or black colour, opaque, sectile, and soils the fingers. Though its specific gravity is as high as 3.706, it appears very light in the hand, but imbibes water with violence, and immediately sinks when immersed. Mixed with linseed oil it inflames spontaneously. The localities of black-wadd are particularly Devonshire and Cornwall. The dendritic delineations, often so beautiful upon limestone, steatite, and other substances, are supposed to derive their colouring matter from this mineral. It is used as a drying ingredient in paints.