bieberite

{{Infobox mineral | name = Bieberite | category = Sulfate mineral | image = Bieberite, Bismuth-466347.jpg | imagesize = | alt = | caption = A 4.4 by 2.7 cm mass of mainly grey bismuth covered by a thin film of pinkish bieberite from an old classic Locality, Schlema, Schlema-Hartenstein District, Erzgebirge, Saxony, Germany | formula = CoSO4·7H2O | IMAsymbol=Bie | molweight = | strunz = 7.CB.35 | dana = 29.6.10.4 | system = Monoclinic | class = Prismatic (2/m) | symmetry = P2/m | unit cell = | color = Rose-red, red-pink, flesh-red | habit = Crusts, stalactites | twinning = | cleavage = {001} perfect, {110} fair | fracture = | tenacity = | mohs = 2 | luster = Vitreous | refractive = | opticalprop = Biaxial (+), colorless to pale rose color (transmitted light) | birefringence = | 2V = 88° (measured), 88° (calculated) | pleochroism = | streak = | gravity = 1.96 | density = 1.96 (measured), 1.83 (calculated) | melt = | fusibility = | diagnostic = | solubility = Soluble in water | diaphaneity = Subtransparent | other = | references = }}

Bieberite (CoSO4 · 7H2O) is a pinkish red colored sulfate mineral high in cobalt content. The name is derived from the type locality at the copper deposit in Bieber, Hesse, Germany. It has been described and reported as far back as the 1700s. Bieberite primarily occurs as a secondary mineral, forming in cobalt-bearing arsenide and sulfide deposits through oxidation.