Playfairite is a very rare sulfosalt mineral with chemical formula Pb₁₆Sb₁₈S₄₃ in the monoclinic crystal system, named after the Scottish scientist and mathematician John Playfair. It was discovered in 1966 by the Canadian mineralogist John Leslie Jambor. Lead gray to black in colour, its lustre is metallic. Playfairite shows strong reflection pleochroism from white to brownish gray. Playfairite has a hardness of 3.5 to 4 on Mohs scale and a density of approximately 6.44.