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Hausmannite
Hausmannite is oxides (manganese spinel-type), Mn2+Mn3+2O4. In the hand, it rates 5.5 on the Mohs scale, and it runs brownish black and iron black. Brown-black pseudo-octahedra with submetallic shine and a chestnut-brown streak, the showy South African crystals often sit with green andradite druse.
The geology.
Hausmannite carries the formula Mn2+Mn3+2O4. It belongs to the tetragonal system. Catalogues list it as oxides (manganese spinel-type).
It sits at 5.5 on the Mohs scale. The surface reads submetallic. Light behaviour is opaque. Specific gravity runs 4.7 to 4.84. The streak is chestnut brown. It breaks with good basal cleavage; uneven fracture.
Brown-black pseudo-octahedra with submetallic shine and a chestnut-brown streak, the showy South African crystals often sit with green andradite druse.
It reaches buyers as sharp pseudo-octahedral crystals, granular masses or crystals with andradite.
The origins.
Metamorphosed manganese deposits: Kalahari manganese field (N'Chwaning mines, South Africa) for world-best crystals; Germany, India, Brazil.
On value, the database notes: collector mineral; lustrous Kalahari crystals are premium specimens.
Traditional associations.
In energy work traditions, associated with deep grounding and composure in chaotic settings.
We keep this section because people ask. It sits below the geology on purpose, and none of it describes something the stone does.
Spotting the real thing.
Brown-black pseudo-octahedra with submetallic shine and a chestnut-brown streak, the showy South African crystals often sit with green andradite druse.
Not faked; magnetite mislabels are the common error.
| Looks like | How to tell them apart |
|---|---|
| Magnetite | Magnetite is strongly magnetic with black streak; hausmannite is weakly magnetic at best with brown streak |
| Franklinite | Franklinite streaks red-brown to black and comes from zinc ores; locality and analysis separate them |
| Chromite | Chromite streaks dark brown but occurs in ultramafic rock, not manganese ore |
At-home tests.
Before anyone talks you into a lab report, these are the checks worth doing yourself on hausmannite.
| Test | What you should see |
|---|---|
| By eye | Chestnut streak on porcelain |
| Magnet check | Not (or barely) attracted to a magnet |
| By eye | Octahedron-like crystal silhouette |
Anything that scratches, burns or dissolves the piece is a lab job. Get it appraised rather than testing it apart.
Care & handling.
At 5.5 on the Mohs scale it handles careful wear but scratches against quartz and dust. Store it separately and take rings off before rough work.
It breaks with good basal cleavage; uneven fracture, which is worth knowing before you set it or drop it.
Warm water and a soft cloth clean almost everything. Ultrasonic tanks, steamers and household cleaners are where pieces get ruined.
Manganese oxide: avoid inhaling dust from broken or sawn pieces.
A deeper look.
Extended detail on composition, sourcing, authentication and market value.
The physical record
The formula on record is Mn2+Mn3+2O4. Crystal system: Tetragonal. Specific gravity: 4.7 to 4.84. Streak: Chestnut brown. Cleavage and fracture: Good basal cleavage; uneven fracture.
How it reaches the market
Metamorphosed manganese deposits: Kalahari manganese field (N'Chwaning mines, South Africa) for world-best crystals; Germany, India, Brazil.
What it gets confused with
Magnetite: Magnetite is strongly magnetic with black streak; hausmannite is weakly magnetic at best with brown streak. Franklinite: Franklinite streaks red-brown to black and comes from zinc ores; locality and analysis separate them. Chromite: Chromite streaks dark brown but occurs in ultramafic rock, not manganese ore.
What it is worth
Collector mineral; lustrous Kalahari crystals are premium specimens.
Where buyers get caught
Not faked; magnetite mislabels are the common error.
One more thing
N'Chwaning hausmannite crystals are so sharp and lustrous that miners once mistook pockets of them for galena until the streak test told the truth.
An education-first guide.
No product links here. We do not sell hausmannite, and a guide that only covers our own shelves would not be much of a guide.
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