Mooreite
Mooreite is an IMA-recognized mineral species in the sulfate class, with the chemical formula Mg₁₅(SO₄)₂(OH)₂₆·8H₂O.
It crystallizes in the monoclinic crystal system (space group P2_1/m).
Key properties: Mohs hardness 3; specific gravity 2.47; Vitreous luster; optically biaxial.
IMA symbol Mre, grandfathered status — known before the IMA’s founding, named in 1929.
Rarely in cavities and veinlets in franklinite–willemite–calcite ore from a metamorphosed stratiform zinc orebody.
It is found associated with Pyrochroite, rhodochrosite, zincite, torreyite, fluoborite, franklinite, willemite, calcite.
The mineral was named to honor Dr. Gideon Emmet Moore (1842–1895), University of California, Berkeley, California, USA, American chemist, an early investigator of Franklin and Sterling Hill minerals.