Gillardite , Gaspéite Locality: 132 North Mine, Widgiemooltha, Western Australia , Australia ( Locality at mindat.org ) Size: 5.2 x 4.4 x 2.7 cm. Gillardite is an extremely rare copper nickel chlorine halide, found only at this locality to date. This is a very rare attractive specimen that is just loaded with crystalline gillardite, perched on lighter-green gaspeite. This mineral seldom crystallizes and although small, these crystals are discrete and eye-visible. — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Gillardite
Gillardite is an IMA-recognized mineral species in the halide class, with the chemical formula Cu₃NiCl₂(OH)₆.
It crystallizes in the hexagonal crystal system (space group R-3m). It is a member of the Atacamite structural group.
Key properties: Mohs hardness 3; specific gravity 3.76; Green streak; Vitreous luster; optically uniaxial.
IMA symbol Gla, IMA status: approved, named in 2006.
Found in silicified ferruginous gossan developed on a komatiite-hosted sulfide deposit.
It is found associated with Ni-bearing clinoatacamite.
The mineral was named to honor Professor Robert David Gillard (b. 1936), formerly of the Department of Chemistry, Cardiff University, Wales, UK.