Filipstadite is an extremely rare oxide mineral belonging to the spinel group, known primarily from the Långban mining district in Sweden. It occurs as small, black, metallic octahedral crystals embedded in manganese-rich carbonate rocks. Collectors prize this species for its rarity and its distinct chemical composition involving antimony.
Is this filipstadite?
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 filipstadite with a known reference. Filipstadite sits at Mohs 6-6.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: brown.
- 3Read the lusterHold the specimen under a strong light. Luster: metallic.
- 4Match the color rangeCompare against the expected color range: black, dark brownish gray.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: pseudo octohedral.
Often confused with
Filipstadite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Filipstadite leaves brown, Magnetite leaves black.
How to tell apart: Streak differs, so Filipstadite leaves brown, Hausmannite leaves dark reddish brown; luster reads metallic on Filipstadite and submetallic on Hausmannite.
Often found alongside filipstadite
Minerals reported to co-occur with filipstadite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Fe₀.₅Sb₀.₅)Mn₂O₄
- Mohs hardness
- 6-6.5
- Density
- 4.9 g/cm³
- Colors
- BlackDark brownish gray
- Streak
- Brown
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Orthorhombic
- Crystal habit
- Pseudo octohedral
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In metamorphosed Fe–Mn orebodies
Where rockhounds find filipstadite
Classic worldwide localities
- Långban and Jakobsberg, Värmland, Sweden
Field-hunting tip
Where it forms: In metamorphosed Fe–Mn orebodies. If you start seeing jacobsite, ingersonite, calcite in float, you are in the right ground. Typical habit: pseudo octohedral. Train your eye for that shape before scanning the outcrop.
Common questions
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What rocks look like filipstadite?+
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Find filipstadite on the map
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