Aikinite

Aikinite is a sulfide mineral of lead, copper and bismuth with formula PbCuBiS₃. It forms black to grey or reddish brown acicular orthorhombic crystals with a Mohs hardness of 2 to 2.5 and a specific gravity of 6.1 to 6.8. It was originally found in 1843 in the Beryozovskoye deposit, Ural Mountains. It is named after Arthur Aikin (1773–1854), an English geologist.