Metarauchite is a very rare secondary uranium-nickel arsenate mineral typically found as a result of the dehydration of rauchite. It commonly appears as small, thin, yellow tabular crystals or crusts within hydrothermal vein systems rich in nickel and uranium.
Is this metarauchite?
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 metarauchite with a known reference. Metarauchite sits at Mohs 2 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Metarauchite leaves a yellow streak.
- 3Read the lusterHold the specimen under a strong light. Metarauchite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: yellow, yellow-green.
- 5Look at form & habitCrystal system: triclinic. Typical habit: tabular crystals, crusts.
Often confused with
Metarauchite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside metarauchite
Minerals reported to co-occur with metarauchite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ni(UO₂)₂(AsO₄)₂·8H₂O
- Mohs hardness
- 2
- Density
- 4.21 g/cm³
- Colors
- Streak
- Yellow
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Triclinic
- Crystal habit
- Tabular Crystals, Crusts
- Cleavage
- Perfect
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Hydrothermal Veins
- Typical price
- $50-300 per specimen
Where rockhounds find metarauchite
Classic worldwide localities
- Jáchymov, Czech Republic
- Schneeberg, Germany
Field-hunting tip
Look in hydrothermal veins country — that is the host setting where metarauchite typically forms. If you start seeing rauchite, uraninite, nickelskutterudite in float, you are in the right ground. Field specimens usually show a tabular crystals, crusts habit, so train your eye for that shape before scanning the outcrop.




