Manganite
Chemical Formula	MnO(OH)
Species	Oxides & Hydroxides
Crystal System	Monoclinic
Mohs Scale	4
Specific Gravity	4.29-4.34
Color	Dark steel-gray to black, reddish brown in transmitted light, gray-white with brownish tint, with blood-red internal reflections in reflected light
Streak	Reddish brown to nearly black
Luster	Sub-Metallic
Refractive Index	n = 2.250(2) n = 2.250(2) n = 2.530(2)
Diaphaneity	Opaque
Cleavage	Perfect perfect; and good.
Fracture	Irregular/Uneven
Crystal Habit：Slender prismatic crystals, massive to fibrous
Geological Setting：Low temperature hydrothermal or hot spring manganese deposits. Sedimentary deposits.