Torbernite
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 NameTorbernite
Chemical FormulaCu(UO₂)₂(PO₄)₂·8–12H₂O
Mohs Hardness2
Crystal Systemtetragonal
Lustervitreous
Streak Colorpale green
Cleavageperfect on {001}
Fractureuneven
Specific Gravity3.22
Colorsemerald green, grass green, apple green
Transparencytransparent
Type LocalityGunnislake Area, Callington District, Cornwall, England, UK
Mineral GroupPhosphates
Usesminor ore of uranium, collector
Associated Mineralsuraninite, autunite, zeunerite, quartz, limonite
Rarityuncommon
Description
This specimen displays vibrant emerald green, tabular torbernite crystals, some forming aggregates, embedded within a light-colored, possibly quartz-rich matrix with darker inclusions and reddish-brown staining.
Geological Context
Torbernite is a secondary uranium mineral that forms in the oxidized zones of uranium-bearing hydrothermal deposits and pegmatites, typically as an alteration product of primary uranium minerals like uraninite.
