Curienite is a rare uranyl vanadate mineral that forms as vibrant yellow, platy crystals, often associated with other uranium-bearing minerals in oxidized zones. It is primarily sought after by advanced collectors for its striking color and radioactive properties, typically found as crusts or small aggregates on host rocks.
Is this curienite?
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 curienite with a known reference. Curienite sits at Mohs 3, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: light yellow.
- 3Read the lusterHold the specimen under a strong light. Luster: adamantine to pearly.
- 4Match the color rangeCompare against the expected color range: canary yellow.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: platy crystals, crusts, micaceous aggregates.
Often confused with
Curienite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Curienite is noticeably harder (Mohs 3 vs. 2); streak differs, so Curienite leaves light yellow, Carnotite leaves strontian-yellow; luster reads adamantine to pearly on Curienite and dull, earthy; silky when crystalline on Carnotite.
How to tell apart: Curienite is noticeably harder (Mohs 3 vs. ~2).
How to tell apart: Streak differs, so Curienite leaves light yellow, Meta-autunite leaves yellow; luster reads adamantine to pearly on Curienite and pearly to dull on Meta-autunite.
Often found alongside curienite
Minerals reported to co-occur with curienite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Pb(UO₂)₂(VO₄)₂·5H₂O
- Mohs hardness
- 3
- Density
- 4.88 g/cm³
- Colors
- Streak
- Light yellow
- Luster
- Adamantine to pearly
- Transparency
- Semitransparent
- Crystal system
- Orthorhombic
- Crystal habit
- Platy crystals, crusts, micaceous aggregates
- Cleavage
- Perfect
- Fluorescence
- Bright yellow-green under UV
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In the oxidized zone of a Pb-bearing U–V deposit (Mounana mine, Gabon)
Where rockhounds find curienite
Classic worldwide localities
- Mounana uranium mine, Franceville, Gabon
- Abertamy uranium mine, near Jáchymov, and in the Geister vein, Jáchymov (Joachimsthal), Czech Republic
- Akashat, Iraq
Field-hunting tip
Where it forms: In the oxidized zone of a Pb-bearing U–V deposit (Mounana mine, Gabon). If you start seeing francevillite, duttonite, vanuralite in float, you are in the right ground. Typical habit: platy crystals, crusts, micaceous aggregates. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify curienite?+
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Find curienite on the map
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