Manganite - Mn³⁺O(OH)

Habit: Crystals pseudo-orthorhombic, short to long prismatic with Striations parallel to their length. Typically dark steel-grey to iron-black. Crystals often grouped in bundles or markedly composite, rarely massive, stalactitic. Opaque, transparent on thin edges, subMetallic Luster.

Environment: Occurs as a low-temperature Hydrothermal deposits associated with baryte, calcite and siderite; in replacement deposits with goethite; and in shallow marine deposits, lakes and bogs.

Etymology: Named for its composition