uranophane

{{Infobox mineral | name = Uranophane | boxwidth = | boxbgcolor = | image = Uranophane.jpg | imagesize = 260px | alt = | caption = | category = Uranyl neso- and polysilicates | formula = Ca(UO2)2[HSiO4]2·5H2O | molweight = 586.36 g/mol |IMAsymbol=Urp-α | strunz = 9.AK.15 | dana = | system = Monoclinic | class = Sphenoidal (2) (same H-M symbol) | symmetry = P21 | unit cell = a = 15.85 Å, b = 6.98 Å c = 6.64 Å; β = 97.45°; Z = 2 | color = Light yellow, lemon-yellow, honey-yellow, straw-yellow, green-yellow | colour = | habit = Crystals occur as stellate needle aggregates; as fibrous crusts, and massive | twinning = | cleavage = {100} Perfect | fracture = Uneven | tenacity = Brittle | mohs = 2.5 | luster = Vitreous to pearly; waxy or dull when massive | streak = Yellowish white | diaphaneity = Translucent to subtranslucent | gravity = 3.81–3.90 | density = | polish = | opticalprop = Biaxial (−) | refractive = nα = 1.643 nβ = 1.666 nγ = 1.669 | birefringence = δ = 0.026 | pleochroism = Weak; X = colorless; Y = pale canary-yellow; Z = canary-yellow | 2V = 32° to 45°, measured | dispersion = | extinction = | length fast/slow = | fluorescence = Weak yellow-green under both short and long UV | absorption = | melt = | fusibility = | diagnostic = | solubility = | impurities = | alteration = | other = 25px Radioactive | prop1 = | prop1text = | references = }}

Uranophane (Ca(UO2)2(SiO3OH)2·5H2O), also known as uranotile, is a rare calcium uranium silicate hydrate mineral that forms from the oxidation of other uranium-bearing minerals. It has a yellow color and is radioactive.