Oberthürite is a rare rhodium nickel sulfide. It occurs in a heavy-mineral concentrate from coarse-grained ophitic olivine gabbro. It was first described from W Horizon, Marathon Cu-PGE-Au deposit, Coldwell alkaline complex, Ontario, Canada.
Is this oberthürite?
4-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 oberthürite with a known reference. Oberthürite sits at Mohs 3.5-4, softer than the next harder reference, harder than the previous one.
- 2Read the lusterHold the specimen under a strong light. Luster: metallic.
- 3Match the color rangeCompare against the expected color range: creamy brown compared, coldwellite and bornite, white compared, torryweiserite, and gray compared, chalcopyrite and millerite.
- 4Look at form & habitCrystal system: cubic. Typical habit: massive.
Often confused with
Oberthürite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside oberthürite
Minerals reported to co-occur with oberthürite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Rh₃Ni₃₂S₃₂
- Mohs hardness
- 3.5-4
- Density
- 5.195 g/cm³
- Colors
- Creamy brown comparedColdwellite and borniteWhite comparedTorryweiseriteAnd gray comparedChalcopyrite and millerite
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Cubic
- Crystal habit
- Massive
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In a heavy-mineral concentrate from coarse-grained ophitic olivine gabbro
Where rockhounds find oberthürite
Classic worldwide localities
- W Horizon, Marathon Cu-PGE-Au deposit, Coldwell alkaline complex, Ontario, Canada
Field-hunting tip
Where it forms: In a heavy-mineral concentrate from coarse-grained ophitic olivine gabbro. If you start seeing vysotskite, au-ag alloy, isoferroplatinum in float, you are in the right ground. Typical habit: massive. Train your eye for that shape before scanning the outcrop.




