| Janggunite | |
| Category: | Oxide mineral |
| Imasymbol: | Jgn[1] |
| Strunz: | 4.FG.05 |
| Symmetry: | Pman |
| Unit Cell: | a = 9.324, b =14.05 c = 7.956 [Å], Z = 4 |
| Color: | Black |
| Cleavage: | Perfect, one direction |
| Tenacity: | Fragile |
| Mohs: | 2 - 3 |
| Luster: | Dull |
| Streak: | Brownish black to dark brown |
| Gravity: | 3.59 |
| Opticalprop: | Biaxial |
| References: | [2] [3] [4] |
Janggunite is a rare manganese oxide mineral with the chemical formula .
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]