quintinite

{{Infobox mineral | name = Quintinite | category = Carbonate mineral | boxwidth = | boxbgcolor = | image = Quintinite-501988.jpg | imagesize = 260px | caption = Quintinite-2H | formula = Mg4Al2(OH)12CO3·3H2O | IMAsymbol = Qtn | strunz = 5.DA.40 | system = 2H polytype: Hexagonal 3T polytype: Trigonal | class = Trapezohedral (622) H-M symbol: (6 2 2) | symmetry = P6322 | unit cell = a = 10.571, c = 15.171 [Å], Z = 4 | molweight = | color = Colorless, deep orange red, orange, pale brown | habit = Prismatic – crystals shaped like slender prisms | twinning = | cleavage = {0001} perfect | fracture = | tenacity = | mohs = 2 | luster = Vitreous | refractive = 1.533 (isotropic) | opticalprop = Uniaxial (±) for 2H type, uniaxial negative, for 3T polytype, uniaxial negative or positive | pleochroism = For 2H polytype, O=yellow, E=lighter yellow; For 3T polytype, typically nonpleochroic | streak = White | gravity = 2.14 | density = | melt = | fusibility = | diagnostic = | solubility = | diaphaneity = Transparent | other = | references = }}

Quintinite is a carbonate mineral with the chemical formula Mg4Al2(OH)12CO3⋅3H2O.