Goldhillite

goldhillite

mixite

cornwallite

conichalcite

Images

Formula: Cu5Zn(AsO4)2(OH)6.H2O
Hydrated arsenate of copper and zinc, end member of the goldhillite-philipsburgite-kipushite series
Crystal System: Monoclinic
Specific gravity: 4.199 calculated
Hardness: 3½
Colour: Bright emerald-green
Environments

Hydrothermal environments

Goldhillite was approved as a new mineral in 2021, but some earlier specimens labelled as philipsburgite may in fact be goldhillite.

Localities

At the Carisa Mine, Mammoth, Tintic Mining District, Juab County, Utah, USA, goldhillite was originally identified as philipsburgite. The goldhillite occurred as green spheres composed of platy crystals on a single boulder, in a very heavily oxidised matrix composed mostly of brown goethite. The size of the individual spheres is about a millimetre or two, with good coverage of the host matrix (MinRec 55.2.204-205).

Goldhillite from the Carisa Mine - Image

At the type locality, Middle pit, Gold Hill Mine, Gold Hill, Gold Hill Mining District, Tooele County, Utah, USA, goldhillite occurs on fracture surfaces in a rock comprised mostly of quartz with iron hydroxides in association with mixite, cornwallite and conichalcite.
Goldhillite forms transparent, bright emerald-green, tabular crystals with vitreous lustre (MM 86.436-446).

Goldhillite from the Middle Pit - Image

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