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
Colorado Mineral Belt about 25 million years. Colorado Mineral Belt The Colorado Mineral Belt (CMB) is an area of ore deposits from the La Plata Mountains in Southwestern Colorado to near the middle of the state at Boulder, Colorado and from which over 25 million troy ounces (778 t) of gold were extracted beginning in 1858. The belt is a "northeast-striking zone defined by: a Proterozoic shear zone system (McCoy, 2001); a suite of Laramide-aged plutons and related ore deposits (Tweto and Sims, 1963); a major gravity low (Isaacson and Smithson, 1976); low-crustal velocities; and high heat flow (Decker et al., 1988)." Mining