Chemistry:Manganosite

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Manganosite
Zincite-Manganosite-Sonolite-21568.jpg
Black manganosite crystals with zincite and sonolite
General
CategoryOxide mineral
Formula
(repeating unit)
Manganese oxide, MnO
Strunz classification4.AB.25
Crystal systemCubic
Crystal classHexoctahedral (m3m)
H-M symbol: (4/m 3 2/m)
Space groupFm3m
Unit cella = 4.44 Å; Z = 4
Identification
ColorEmerald-green, becoming black on exposure to air
Crystal habitGranular to massive; Octahedral crystals uncommon
CleavagePerfect on [100], [010] and [001]
FractureFibrous
Mohs scale hardness5 - 6
|re|er}}Vitreous, adamantine to dull
StreakBrown
DiaphaneityTransparent to translucent
Specific gravity5.364
Optical propertiesIsotropic
Refractive indexn = 2.16–2.17
References[1][2][3][4]

Manganosite is a rare mineral composed of manganese(II) oxide MnO. It was first described in 1817 for an occurrence in the Harz Mountains, Saxony-Anhalt, Germany .[3] It has also been reported from Langban and Nordmark, Sweden and at Franklin Furnace, New Jersey. It also occurs in Japan , Kyrgyzstan and Burkina Faso.[4]

It occurs in manganese nodules. It also occurs as alteration of manganese minerals such as rhodocrosite during low oxygen metamorphism and metasomatism.[4]

References