beudantite

{{Infobox mineral | name = Beudantite | category = Arsenate minerals | image = Beudantite-ea12a.jpg | imagesize = 170px | alt = | caption = Large brown crystals of beudantite | formula = PbFe3(OH)6SO4AsO4 | IMAsymbol=Bdn | molweight = | strunz = 8.BL.10 | dana = 43.4.1.1 | system = Trigonal | class = Hexagonal scalenohedral (m) H-M symbol: ( 2/m) | symmetry = Rm | unit cell = a = 7.32 Å, c = 17.02 Å; Z = 3 | color = black, dark green, brown, yellowish, red, greenish yellow, brown | habit = tabular, acute rhombohedral, pseudo-cubic, pseudo-cuboctahedral | twinning = | cleavage = distinct; good on {0001} | fracture = | tenacity = | mohs = 3.5–4.5 | luster = vitreous, resinous | refractive = nω = 1.957 nε = 1.943 | opticalprop = Uniaxial (−) | birefringence = δ = 0.014 | pleochroism = visible | 2V = | dispersion = | streak = grayish yellow to green | gravity = 4.48 | density = | melt = | fusibility = | diagnostic = | solubility = | diaphaneity = transparent, translucent | other = Soluble in HCl |references = }}

Beudandite is a secondary mineral occurring in the oxidized zones of polymetallic deposits. It is a lead, iron, arsenate, sulfate with endmember formula: PbFe3(OH)6SO4AsO4.