Gunningite

gunningite

Images

Formula: Zn(SO4).H2O
Hydrated sulphate, kieserite group
Crystal System: Monoclinic
Specific gravity: 3.195 measured, 3.369 calculated
Hardness: 2½
Streak: White
Colour: White to colourless
Solubility: Rapidly soluble in cold water
Environments


Gunningite is of rare occurrence in dry areas of the oxidised portions of sphalerite-bearing deposits; it also occurs as a post-mining efflorescence on museum specimens (HOM).
It may originate as a dehydration product of boyleite (Mindat).

Localities

At the Willett mine, near Lardeau, Revelstoke Mining Division, British Columbia, Canada, gunningite is associated with woodruffite and smithsonite (HOM).

There are two co-type localities, the Hector-Calumet mine, Calumet, Galena Hill, and the Comstock-Keno Mine, Keno Hill, both in the Mayo mining district, Yukon, Canada.

At the Hector-Calumet mine, Calumet, Galena Hill, Mayo mining district, Yukon, Canada, gunningite has been found (Mindat photo).
Gunningite from the Hector-Calumet Mine - Image

At the Comstock-Keno Mine, Keno Hill, Mayo mining district, Yukon, Canada, the deposits are veins and lodes in faults that cut quartzite, phyllite, schist and greenstone.
The principal primary minerals are siderite, quartz, galena, sphalerite, chalcopyrite, pyrite, arsenopyrite and freibergite. These are altered in the zones of oxidation to limonite, various hydrous manganese oxides, scorodite, jarosite, beudantite, bindheimite, cerussite, malachite, azurite, smithsonite, anglesite and gypsum. In addition some native silver, pyrargyrite and hawleyite occur in both the zones of oxidation and reduction.
The gunningite is generally found closely associated with incipiently oxidised sphalerite in the veins and lodes and on the old mine dumps. In the deposits, the mineral is present in those parts that are relatively dry, and on the dumps the gunningtonite appears on the oxidising sphalerite after long periods of hot dry weather. In all occurrences the gunningite appears as delicate efflorescences directly on the surface of sphalerite, or as efflorescences on limonite, scorodite, gypsum, and other supergene minerals closely associated with the zinc sulphide (CM 7.209-218).

At Les Valettes, Mont Chemin mining district, Martigny, Valais, Switzerland, gunningite is associated with boyleite, coquimbite, zincocopiapite, jarosite, melanterite, römerite, siderotil, voltaite, chalcanthite, hexahydrite and gypsum (HOM).

At the Goldstrike Mines, Nevada, USA, gunningite is associated with szomolnokite, starkeyite, anhydrite and gypsum (HOM).

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