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www.mineralgallery.co.za Minerals K-O |
Manganite
Name
Manganite
Chemistry
MnO(OH), Manganese Oxide Hydroxide
Uses
A minor source of manganese and as a mineral specimen
Color
Black to steel gray
Hardness
4
Specific gravity
4.3
Manganite usually occurs as short prismatic crystals that have a psuedo-orthorhombic shape. The terminations are generally blunted with domes and minor pyramid faces. The crystals are striated lengthwise. Crystals are usually grouped into tight bundles and columnar, massive and fibrous forms are also known. Penetration and contact twinning does occasionally occur.
Manganite was a valuable manganese ore when it was found in plentiful deposits. Now its rarity has relegated it to the standing of a minor ore despite its high manganese content. Crystals are the chief indicator for identification. Only a few metallic minerals will have similar crystals (such as enargite) and these can be eliminated by means of comparing manganite's reddish streak and hardness.
Pyrolusite is softer and has a bluish streak. If Manganite is massive, it is difficult to distinguish it from other manganese minerals. Fine crystals of Manganite can make a nice addition to a mineral collection
Associated Minerals are calcite, barite, garnets, limonite, siderite, pyrolusite and other manganese minerals. Other Characteristics: Alters to pyrolusite which can coat the crystals, dulling the luster and can affect a streak test.
