Janggunite
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Janggunite is a rare manganese oxide mineral with the chemical formula Mn5−x(Mn,Fe)1+xO8(OH)6.
| Janggunite | |
|---|---|
Janggunite found in South Korea | |
| General | |
| Category | Oxide mineral |
| Formula | Mn5−x(Mn,Fe)1+xO8(OH)6 |
| IMA symbol | Jgn[1] |
| Strunz classification | 4.FG.05 |
| Crystal system | Orthorhombic |
| Space group | Pman |
| Unit cell | a = 9.324, b =14.05 c = 7.956 [Å], Z = 4 |
| Identification | |
| Color | Black |
| Cleavage | Perfect, one direction |
| Tenacity | Fragile |
| Mohs scale hardness | 2 - 3 |
| Luster | Dull |
| Streak | Brownish black to dark brown |
| Specific gravity | 3.59 |
| Optical properties | Biaxial |
| References | [2][3][4] |
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]