Manganosite

Manganosite
Black manganosite crystals with zincite and sonolite
General
CategoryOxide mineral
Formula
(repeating unit)
Manganese oxide, MnO
IMA symbolMng[1]
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
LusterVitreous, adamantine to dull
StreakBrown
DiaphaneityTransparent to translucent
Specific gravity5.364
Optical propertiesIsotropic
Refractive indexn = 2.16–2.17
References[2][3][4][5]

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.[4] 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.[5]

It occurs in manganese nodules. It also occurs as alteration of manganese minerals such as rhodocrosite during low oxygen metamorphism and metasomatism.[5]

  1. ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
  2. ^ Mineralienatlas
  3. ^ Manganosite data on Webmineral
  4. ^ a b Manganosite data from Mindat.org
  5. ^ a b c Manganosite in the Handbook of Mineralogy