The Battle of Grand Gulf was fought on April 29, 1863, during th: Sphalerite is a sulfide mineral with the chemical formula (Zn,Fe)S. It is found in a variety of deposit types, and is found in association with galena, chalcopyrite, pyrite (and other sulfides), calcite, dolomite, quartz, rhodochrosite, and fluorite. Sphalerite is an important ore of zinc, with around 95 percent of all primary zinc extracted from its ore. Due to its variable trace-element content, sphalerite is also an important source of several other metals such as cadmium, gallium, germanium and indium. The zinc in sphalerite is also used to produce brass. This sample was extracted in Creede, Colorado, and features black tetrahedral crystals of sphalerite up to 8 mm (0.31 in) in size, with minor chalcopyrite and calcite, in a 4.5 cm × 3.0 cm × 2.0 cm (1.77 in × 1.18 in × 0.79 in) matrix. This photograph was focus-stacked from 125 separate images.