Autunite
Image: <bdi><a href="https://www.wikidata.org/wiki/Q56247090" class="extiw" title="d:Q56247090"><span title="mineral collector and dealer">Robert M. Lavinsky</span></a></bdi> (CC BY-SA 3.0)
Mineral NameAutunite
Chemical FormulaCa(UO2)2(PO4)2·10-12H2O
Mohs Hardness2
Crystal Systemtetragonal
Lustervitreous
Streak Colorpale yellow
Cleavageperfect on {001}
Fractureuneven
Specific Gravity3.1
Colorsyellow-green, bright green
Transparencytransparent
Type LocalityDaybreak Mine (Dahl lease), Mount Kit Carson, Spokane County, Washington, USA
Mineral GroupPhosphates
Usesuranium ore, collector's mineral, fluorescent mineral
Associated Mineralsuraninite, torbernite, quartz
Rarityuncommon
Description
This specimen displays numerous bright yellow-green, platy, micaceous crystals of autunite forming a crust on a matrix. The crystals often appear stacked or layered.
Geological Context
Autunite is a secondary uranium mineral, typically forming in the oxidized zones of uranium-bearing pegmatites and hydrothermal deposits as an alteration product of primary uranium minerals.
