Zinkgruvanite crystals in the type specimen. Field of view is 8×5 mm. Catalogue number GEO-NRM 20170502. Photo: Torbjörn Lorin. From the Zinkgruvan Zn-Pb-Ag-Cu deposit, Askersund, Örebro County, Sweden. The image is published in an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license ( https://creativecommons.org/licenses/by/4.0/ ). — Photo: Torbjörn Lorin · CC BY 4.0
Zinkgruvanite
Zinkgruvanite is an IMA-recognized mineral species in the silicate class, with the chemical formula Ba₄Mn²⁺₄Fe³⁺₂(Si₂O₇)₂(SO₄)₂O₂(OH)₂.
It is a member of the Ericssonite structural group.
Key properties: Mohs hardness 4.5; specific gravity 4.42; Dark brown streak; Vitreous to subadamantine (crystal faces), resinous (fractures). Color: Almost black, reddish black (thin fragments) luster; optically biaxial.
IMA symbol Zgv, IMA status: approved, named in 2020.
From a metamorphosed, stratiform, sphalerite and galena-dominated deposit in a succession of interbedded metatuffite, marble, and skarn. Likely syngenetic-exhalative in origin.
It is found associated with Barytocalcite, diopside, baryte, cerchiaraite-Al, cerchiaraite-Fe, witherite, galena, sphalerite, cubanite, chalcopyrite, pyrrhotite, pyrite, zhangpeishanite.
The name is taken from the type locality, the Zinkgruvan mine, Sweden.