White crystals of the rare mineral katerinopoulosite (IMA 2017-004) from the type locality in Lavrion (Esperanza Mine, Lavrion District, Attiki Prefecture, Greece) associated to a bluish green phase that can be niedermayrite. — Photo: David Hospital · CC BY-SA 4.0
Katerinopoulosite
Katerinopoulosite is an IMA-recognized mineral species in the sulfate class, with the chemical formula (NH₄)₂Zn(SO₄)₂·6H₂O.
It crystallizes in the monoclinic crystal system (space group P2_1/a). It is a member of the Picromerite structural group.
Key properties: Mohs hardness 2.5; specific gravity 1.97; White streak; Vitreous luster; optically biaxial.
IMA symbol Kpo, IMA status: approved, named in 2017.
A secondary mineral formed in the oxidation zone of a sphalerite-rich deposit situated in the contact zone between calcite marble and mica schist.
It is found associated with Chalcanthite, nickelboussingaultite, ammoniojarosite, aurichalcite, goethite.
The mineral was named to honor Greek geologist and mineralogist Athanassios Katerinopoulos (b. 1950), director of the Museum of Mineralogy and Petrology and of the Laboratory of Museum Studies.