Sieleckiite Locality: Mount Oxide Copper mine, Mount Gordon, Gunpowder District, Mt Isa - Cloncurry area, Queensland, Australia Blue sieleckiite with green libethenite. Picture width 3 mm. Collection and photograph Christian Rewitzer — Photo: Christian Rewitzer · CC BY-SA 3.0
Sieleckiite
Sieleckiite is an IMA-recognized mineral species in the phosphate class, with the chemical formula Cu₃Al₄(PO₄)₂(OH)₁₂·2H₂O.
It crystallizes in the triclinic crystal system.
Key properties: Mohs hardness 3; specific gravity 3.02; Pale blue streak; Pearly luster; optically biaxial.
IMA symbol Sie, IMA status: approved, named in 1987.
A rare secondary mineral found in a fracture in a boulder from the oxidized zone of a copper deposit.
It is found associated with Variscite, turquoise, libethenite, pseudomalachite.
The mineral was named to honor Robert Sielecki (1958–), Australian geologist, who collected the first specimens.