anthonyite

{{infobox mineral | name = Anthonyite | category = Halide mineral | image = Anthonyite-642442.jpg | imagesize = 260px | alt = | caption = Anthonyite from Mexico | formula = |IMAsymbol=Aty | molweight = | strunz = 3.DA.40 | dana = | system = Monoclinic Space group unknown | class = Prismatic (2/m) (same H-M symbol) | unit cell = | color = Lavender | colour = | habit = Prismatic crystals, commonly curved along [001]; as incrustations | twinning = | cleavage = {100}, good | fracture = | tenacity = Sectile | mohs = 2 | luster = | streak = | diaphaneity = Translucent | gravity = | density = | polish = | opticalprop = Biaxial (−) | refractive = nα = 1.526 nβ = 1.602 nγ = 1.602 | birefringence = δ = 0.076 | pleochroism = X = rich lavender; Y = Z = deep smoky blue | 2V = Measured: 3° | dispersion = | extinction = | length fast/slow = | fluorescence = | absorption = | melt = | fusibility = | diagnostic = | solubility = | impurities = | alteration = | other = | references = }} Anthonyite is a hydrous secondary copper halide mineral with chemical formula of .

It was discovered in 1963 in the Centennial mine, Calumet, Houghton County, Michigan, United States. It was discovered by the University of Arizona mineralogist John W. Anthony (1920–1992), who named it for himself.