GALE'NA, noun [Gr. tranquillity, so named from its supposed effects in mitigating the violence of disease.] Originally, the name of the theriaca.

1. Sulphuret of lead; its common color is that shining bluish gray, usually called lead gray; sometimes it is nearly steel gray. Its streak has a metallic luster, but its fine powder is nearly black. Its structure is commonly foliated, sometimes granular or compact, and sometimes striated or fibrous. It occurs in regular crystals, or more frequently massive.