Minium (mineral) Minium (mineral) Minium is the naturally occurring form of lead tetroxide, PbPbO also known as red lead. Minium is a light-to-vivid red and may have brown-to-yellow tints. It typically occurs in scaly-to-earthy masses. It crystallizes in the tetragonal crystal system. Minium is rare and occurs in lead-mineral deposits that have been subjected to severe oxidizing conditions. It also occurs as a result of mine fires. It is associated with cerussite, galena, litharge, massicot, mimetite, native lead, and wulfenite. It occurs in relatively small amounts throughout the world: Langhecke, Hesse; Badenweiler, Baden-Württemberg; Bleialf, Eifel district; Horhausen (), Rhineland-Palatinate in Germany. It
Stephanite tetrahedrite, galena, sphalerite and pyrite. Localities which have yielded good crystallized specimens are Freiberg and Gersdorf near Rosswein in Saxony, Chañarcillo in Chile, and exceptionally Cornwall. In the Comstock lode in Nevada massive stephanite and argentite are important ores of silver. Stephanite Stephanite is a silver antimony sulfosalt mineral with formula: AgSbS It is composed of 68.8% silver, and sometimes is of importance as an ore of this metal. Under the name Schwarzerz it was mentioned by Georgius Agricola in 1546, and it has been variously known as "black silver ore" (German "Schwarzgultigerz"), brittle silver-ore ("Sprödglanzerz"), etc. The name stephanite