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, green
Transparencytransparent
Type LocalityDaybreak Mine (Dahl lease), Mount Kit Carson, Spokane County, Washington, USA
Mineral GroupPhosphates (Uranyl Phosphate)
Usesuranium ore, collector
Associated Mineralsquartz, feldspar, other uranium minerals
Rarityuncommon
Description
This specimen displays numerous bright yellow-green, platy, tabular crystals forming radiating aggregates on a matrix, giving it a vibrant, leafy appearance.
Geological Context
Autunite is a secondary uranium mineral that forms in the oxidized zone of uranium ore deposits, often as an alteration product of primary uranium minerals like uraninite.
