Photo of a sample of Goslarite — Photo: Geni · CC BY-SA 4.0
Goslarite
A hydrated zinc sulfate of the epsomite group first found at the Rammelsberg mine in Goslar, Germany.
Intro adapted from Wikipedia (CC BY-SA).
Goslarite is an IMA-recognized mineral species in the sulfate class, with the chemical formula Zn(SO₄)·7H₂O.
It crystallizes in the orthorhombic crystal system (space group P2_12_12_1). It is a member of the Epsomite structural group.
Key properties: Mohs hardness 2–2.5; specific gravity 1.98; Vitreous, silky if fibrous luster; refractive index 1.47; optically biaxial.
IMA symbol Gos, grandfathered status — known before the IMA’s founding, named in 1845.
Found as a secondary mineral in oxidized portions of zinc sulfide deposits, particularly as coatings on walls of mine passages.
It is found associated with Epsomite, melanterite, pickeringite, chalcanthite, gypsum.
The name is derived from the locality at Goslar, Germany.