Hausmannite is a heavy, brittle manganese oxide often found as small, shiny black pyramidal crystals. It is typically associated with other manganese minerals in metamorphic deposits and is easily distinguished by its brownish-red streak and submetallic luster.
Is this hausmannite?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch hausmannite with a known reference. Hausmannite sits at Mohs 5.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: dark reddish brown.
- 3Read the lusterHold the specimen under a strong light. Luster: submetallic.
- 4Match the color rangeCompare against the expected color range: brownish black, grayish.
- 5Look at form & habitCrystal system: tetragonal. Typical habit: massive, pseudo octohedral.
Often confused with
Hausmannite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Hausmannite leaves dark reddish brown, Magnetite leaves black; luster reads submetallic on Hausmannite and metallic to submetallic, may be dull on Magnetite.
How to tell apart: Streak differs, so Hausmannite leaves dark reddish brown, Braunite leaves brownish black to steel-gray.
How to tell apart: Streak differs, so Hausmannite leaves dark reddish brown, Pyrolusite leaves black, bluish black; luster reads submetallic on Hausmannite and metallic on Pyrolusite.
Often found alongside hausmannite
Minerals reported to co-occur with hausmannite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Mn²⁺Mn³⁺₂O₄
- Mohs hardness
- 5.5
- Density
- 4.84 g/cm³
- Colors
- Streak
- Dark reddish brown
- Luster
- Submetallic
- Transparency
- Opaque, transparent through thin edges
- Crystal system
- Tetragonal
- Crystal habit
- Massive, pseudo octohedral
- Cleavage
- {001}, perfect; {112} and {011}, indistinct
- Rarity
- Uncommon
- Uses
- Collector, Ore of manganese
- Host rock
- A primary mineral in hydrothermal veins
Where rockhounds find hausmannite
1 mapped spotsClassic worldwide localities
- Olympic Peninsula, a number of Clallam, Jefferson, and Mason Cos., Washington, USA
- Blue Jay mine, Trinity Co., California, USA
- Batesville district, Independence, Izard, and Stone Cos., Arkansas, USA
- Cannon mine, Stambaugh, Iron Co., Michigan, USA
- Ilfeld, Harz Mountains, Germany
- Friedrichroda, Elgersburg, and Öhrenstock, near Ilmenau, Thuringia, Germany
Field-hunting tip
Where it forms: A primary mineral in hydrothermal veins. If you start seeing rhodochrosite, pyrolusite, jacobsite in float, you are in the right ground. Typical habit: massive, pseudo octohedral. Train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in California. Start trip planning there.
Common questions
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Find hausmannite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
