Gunningite is one of the minerals in the Kieserite group, with the chemical formula (Zn, Mn2+)SO4·H2O. It is rare. It is found in dry areas of the oxidized portions of sphalerite-bearing deposits. Its name honors Henry Cecil Gunning (1901–1991) of the Geological Survey of Canada and a Professor at the University of British Columbia.
- Category: Sulfate minerals
- Formula: (Zn, Mn2+)SO4H2O
- Crystal system: Monoclinic
- Crystal class: Prismatic (2/m) (same H-M symbol)
- Color: White to colorless
- Cleavage: Indistinct
- Mohs scale hardness: ~2.5
- Luster: Vitreous
- Diaphaneity: Translucent
- Specific gravity: 3.195
- Optical properties: Biaxial (+)
Occurrence: Of rare occurrence in dry areas of the oxidized portions of sphalerite-bearing deposits; occurs also as a post-mining efflorescence on museum specimens.
It has been noted in mines in Canada (Yukon Territory, British Columbia, and New Brunswick), the United States (Nevada and Arizona), Switzerland (Valais), Greece, Attica, and Germany (Baden-Württemberg).
Association: Sphalerite, scorodite, gypsum, pharmacosiderite, jarosite, arsenopyrite, “limonite” (Keno Hill–Galena Hill district, Canada); woodruffite, smithsonite (Willett mine, Canada); szomolnokite, starkeyite, anhydrite, gypsum (Goldstrike mine, Nevada, USA); boyleite, coquimbite, zincocopiapite, jarosite, melanterite, r¨omerite, siderotil, voltaite, chalcanthite, hexahydrite, gypsum (Les Vallettes, Switzerland).