Threadgoldite Locality: Arcu su Linnarbu, Capoterra, Cagliari Province, Sardinia, Italy Pale yellow tabular crystals of Threadgoldite. Analysed by S.Möckel. Field of view 2 mm. Specimen and photo Leon Hupperichs. — Photo: Leon Hupperichs · CC BY-SA 3.0
Threadgoldite
Threadgoldite is an IMA-recognized mineral species in the phosphate class, with the chemical formula Al(UO₂)₂(PO₄)₂(OH)·8H₂O.
It crystallizes in the monoclinic crystal system (space group C2/c).
Key properties: specific gravity 3.4; Vitreous luster; optically biaxial.
IMA symbol Tdg, IMA status: approved, named in 1978.
A rare secondary mineral found in the uraniferous zone of a complex zoned granite pegmatite.
It is found associated with Meta-autunite, phosphuranylite, phuralumite, bolivarite, upalite, eylettersite, mundite.
The mineral was named to honor Ian Malcomb Threadgold (1929–), Australian mineralogist, University of Sydney, Sydney, Australia.