Betpakdalite-FeFe is a rare secondary mineral typically found in the weathered oxidation zones of ore bodies rich in molybdenum and arsenic. It generally presents as distinct yellow or orange powdery crusts or coatings on host rocks like quartz or iron oxides. Collectors often seek it out for its specific type-locality significance and its formation in complex supergene environments.
Is this betpakdalite-fefe?
2-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 betpakdalite-fefe with a known reference. Betpakdalite-FeFe sits at Mohs 2-3, softer than the next harder reference, harder than the previous one.
- 2Look at form & habitCrystal system: monoclinic. Typical habit: crusts, powdery coatings, microcrystalline aggregates.
Often confused with
Betpakdalite-FeFe vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside betpakdalite-fefe
Minerals reported to co-occur with betpakdalite-fefe. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- [Fe₂(H₂O)₁₅(OH)₂Fe(H₂O)₆][Mo₈As₂Fe₃O₃₇]
- Mohs hardness
- 2-3
- Density
- 3.5-3.8 g/cm³
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Crusts, powdery coatings, microcrystalline aggregates
- Rarity
- Rare
- Uses
- Collector
Where rockhounds find betpakdalite-fefe
Classic worldwide localities
- Mt. Moliagul, ~200 km northwest of Melbourne and 58 km west of Bendigo, Victoria, Australia
Field-hunting tip
If you start seeing molybdenite, goethite, quartz in float, you are in the right ground. Typical habit: crusts, powdery coatings, microcrystalline aggregates. Train your eye for that shape before scanning the outcrop.






