Moorhouseite
Natural cobalt sulfate hexahydrate — a lower-hydrate relative of bieberite and aplowite.
Intro adapted from Wikipedia (CC BY-SA).
Moorhouseite is an IMA-recognized mineral species in the sulfate class, with the chemical formula Co(SO₄)·6H₂O.
It crystallizes in the monoclinic crystal system (space group C2/c). It is a member of the Hexahydrite structural group.
Key properties: Mohs hardness 2.5; specific gravity 1.97–2.02; White streak; Vitreous luster; optically biaxial.
IMA symbol Mh, IMA status: approved, named in 1963.
Occurs as efflorescences with sulfides (probably cobaltian and nickelian pyrite) on siderite–barite matrix from a hydrothermal Pb–Zn–Cu orebody in association with a large barite deposit (Magnet Cove mine, Canada).
It is found associated with Aplowite, siderite, barite (Magnet Cove mine, Canada); koritnignite, köttigite, picropharmacolite (Jáchymov, Czech Republic).
The mineral was named to honor Dr. Walter Wilson Moorhouse (1913–1969), Canadian Professor of Geology, University of Toronto, Toronto, Canada.