What is "jarosewichite"

n. (context mineralogy English) A manganese arsenate hydroxide mineral.

Jarosewichite is a rare manganese arsenate mineral with formula: MnMn(AsO)(OH). It was first described in Franklin, New Jersey which is its only reported occurrence. Its chemical composition and structure are similar to chlorophoenicite. This mineral is orthorhombic with 2/m2/m2/m point group. Its crystals are prismatic or barrel-shaped. The color of jarosewichite is dark red to black. It has subvitreous luster of fracture surfaces and reddish orange streak. This mineral occurs with flinkite, franklinite, andradite and cahnite.