Wilcoxite
Wilcoxite is an IMA-recognized mineral species in the sulfate class, with the chemical formula MgAl(SO₄)₂F·17H₂O.
It crystallizes in the triclinic crystal system (space group P-1). It is a member of the Aubertite structural group.
Key properties: Mohs hardness 1–2; specific gravity 1.58; Greasy luster; optically biaxial.
IMA symbol Wcx, IMA status: approved, named in 1979.
A rare post-mine mineral deposited from solutions derived from an oxidizing breccia zone (Lone Pine mine, New Mexico, USA); in intensely oxidized cassiterite–tourmaline–quartz–polysulfide ore (Deputatskoye deposit, Russia).
It is found associated with Fluorite, gypsum, khademite, lannonite, pyrite (Lone Pine mine, New Mexico, USA); melanterite, fibroferrite, gypsum, goethite, ice (Deputatskoye deposit.
The mineral was named to honor William Wilcox (?–1880), discoverer of the Wilcox district, New Mexico, USA.