Tags: Chemical Substance, Mineral.
Penroseite is a rare selenide mineral with formula (NiCoCu)Se2. It has a gray-steel color and black streak with a hardness of 3. It is an isometric mineral 2/m3. Penroseite was first discovered in 1925 in a Bolivian rhyolite. It was named for Richard Penrose (1863–1931) an economic geologist.Penroseite is a rare mineral found in the Pacajake mines in Bolivia. It was discovered in 1925. It used to be found in fissure veins in the extrusive igneous rhyolite rock.
