aurichalcite

{{Infobox mineral | name = Aurichalcite | category = Carbonate mineral | boxwidth = | boxbgcolor = | image = Aurichalcite-Calcite-aur08b.jpg | imagesize = 260px | alt = | caption = | formula = |IMAsymbol=Ach | strunz = 5.BA.15 | system = Monoclinic | class = Prismatic (2/m) (same H-M symbol) | symmetry = P21/m | unit cell = a = 13.82, b = 6.419 c = 5.29 [Å] β = 101.04°; Z = 2 | color = Pale green, greenish blue, light blue; colorless to pale blue, pale green in transmitted light | habit = Typically in tufted divergent sprays or spherical aggregates, may be in thick crusts; rarely columnar, laminated or granular | twinning = Observed in X-ray patterns | cleavage = {010} and {100} Perfect | fracture = Uneven | mohs = 2 | luster = Pearly, silky | refractive = nα = 1.655 nβ = 1.740 nγ = 1.744 | opticalprop = Biaxial (−) | birefringence = 0.0890 | pleochroism = Weak colorless to pale green | 2V = Measured: 1° to 4°, Calculated: 22° | streak = Light blue | gravity = 3.96 | melt = | fusibility = | diagnostic = | solubility = | diaphaneity = Transparent | other = | references =

}} Aurichalcite is a carbonate mineral, usually found as a secondary mineral in copper and zinc deposits. Its chemical formula is . The zinc to copper ratio is about 5:4. Copper (Cu2+) gives aurichalcite its green-blue colors.