Trichome

Janggunite
Janggunite found in South Korea
General
CategoryOxide mineral
Formula
(repeating unit)
Mn5−x(Mn,Fe)1+xO8(OH)6
IMA symbolJgn[1]
Strunz classification4.FG.05
Crystal systemOrthorhombic
Space groupPman
Unit cella = 9.324, b =14.05
c = 7.956 [Å], Z = 4
Identification
ColorBlack
CleavagePerfect, one direction
TenacityFragile
Mohs scale hardness2 - 3
LusterDull
StreakBrownish black to dark brown
Specific gravity3.59
Optical propertiesBiaxial
References[2][3][4]

Janggunite is a rare manganese oxide mineral with the chemical formula Mn5−x(Mn,Fe)1+xO8(OH)6.

It was first described in 1975 for an occurrence in the Janggun mine, Bonghwa-gun, Gyeongsangbuk-do, South Korea and named for the locality.[3]

References[edit]


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