Jordanite

Jordanite is a sulfosalt mineral with chemical formula Pb14(As,Sb)6S23 in the monoclinic crystal system, named after the German scientist H. Jordan (1808–1887) who discovered it in 1864.

Lead-grey in colour (frequently displaying an iridescent tarnish), its streak is black and its lustre is metallic. Jordanite has a hardness of 3 on Mohs scale, has a density of approximately 6.4, and a conchoidal fracture.

The type locality is the Lengenbach Quarry in the Binn Valley, Wallis, Switzerland.