PbS Composition Lead sulfide. May contain impurities, such as silver, arsenic, antimony, and copper.
Dodecahedrons are far less common.
Also occurs massive , grainy , fibrous , platy , and as veins . Turns somewhat dull after exposure to air. Cleavage 1,3 - Cubic. May exhibit parting on octahedrons. Lead Glance Varieties Acerila - Term used in a few South American countries describing granular Galena.