Jarosewichite
A rare manganese arsenate known only from Franklin, New Jersey — chemically akin to chlorophoenicite.
Intro adapted from Wikipedia (CC BY-SA).
Jarosewichite is an IMA-recognized mineral species in the arsenate class, with the chemical formula Mn³⁺Mn²⁺₃(AsO₄)(OH)₆.
It crystallizes in the orthorhombic crystal system.
Key properties: Mohs hardness 4; specific gravity 3.66; Reddish orange streak; Subvitreous on fractured surfaces luster; optically biaxial.
IMA symbol Jrw, IMA status: approved, named in 1981.
Found in a mine-dump specimen, incrusting vugs in zinc ore from a metamorphosed stratiform zinc orebody.
It is found associated with Flinkite, cahnite, allactite, hausmannite, andradite, franklinite.
The mineral was named to honor Eugene Jarosewich (1926–), Chief Chemist, Department of Mineral Sciences, Smithsonian Institution, Washington, D.C., USA.