liebigite

{{Infobox mineral | name = Liebigite | image = Liebigite-171838.jpg | alt = | caption = Liebigite crystals from the Ralston Buttes District, Jefferson County, Colorado | category = Carbonate mineral | formula = Ca2(UO2)(CO3)3·11H2O | IMAsymbol = Lbi | strunz = 5.ED.20 | system = Orthorhombic | class = Pyramidal (mm2) (same H-M symbol) | symmetry = Bba2 | unit cell = a = 16.699, b = 17.557 c = 13.697 [Å]; Z = 8 | colour = Green to yellowish-green | habit = Rare as short prismatic crystals; scaly or granular, in aggregates, crusts, and films | twinning = | cleavage = Distinct on {100} | fracture = | tenacity = Brittle | mohs = – 3 | lustre = Vitreous, pearly | streak = | diaphaneity = Transparent, translucent | gravity = 2.41 | density = | polish = | opticalprop = Biaxial (+) | refractive = nα = 1.497 nβ = 1.502 nγ = 1.539 | birefringence = δ = 0.042 | pleochroism = Visible: X = nearly colourless Y = Z = light yellowish green | 2V = 37° to 42° | dispersion = | extinction = | length fast/slow = | fluorescence = Strong green to blue-green under short and long wave UV | absorption = | melt = | fusibility = | diagnostic = | solubility = | impurities = | alteration = | other = 25px Radioactive | references = }}

Liebigite is a uranium carbonate mineral with the chemical formula: Ca2(UO2)(CO3)3·11H2O. It is a secondary mineral occurring in the oxidizing zone of uranium-bearing ores. It is green to yellow green in colour. It has a Mohs hardness of about 3. Liebigite, like some other uranium minerals, is fluorescent under UV light and is also translucent. It crystallizes in the orthorhombic system, but only rarely forms distinct crystals. It typically forms encrustations or granular aggregates.