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.

Hardness

Mohs

Luster

Pearly

Streak

Yellow

Transparency

Translucent

mineralrareMeta-autunite Group family

Curienite

Hardness: 2
Luster: Pearly
Streak: Yellow
Transparency: Translucent

Is this curienite?

5-step field check

Run through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.

1
Test the hardness
Try to scratch curienite with a known reference. Curienite sits at Mohs 2 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Curienite leaves a yellow streak.
3
Read the luster
Hold the specimen under a strong light. Curienite typically shows a pearly luster.
4
Match the color range
Compare against the expected color range: yellow, orange-yellow.
5
Look at form & habit
Crystal 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.

mineral

Carnotite

Mohs 2

How to tell apart: Luster reads pearly on Curienite and dull on Carnotite.

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: 2
Density: 4.15 g/cm³
Colors: Yellow Orange-yellow
Streak: Yellow
Luster: Pearly
Transparency: Translucent
Crystal system: Orthorhombic
Crystal habit: Platy Crystals, Crusts, Micaceous Aggregates
Cleavage: Perfect
Fluorescence: Bright Yellow-green Under UV
Rarity: Rare
Uses: Collector
Host rock: Uranium-vanadium Oxidized Zones
Typical price: $50-500 depending on specimen size and matrix quality

Where rockhounds find curienite

Classic worldwide localities

Mounana Mine, Gabon
Sierra de Alcaraz, Spain
Utah, USA

Field-hunting tip

Look in uranium-vanadium oxidized zones country — that is the host setting where curienite typically forms. If you start seeing vanuralite, francevillite, curite in float, you are in the right ground. Field specimens usually show a platy crystals, crusts, micaceous aggregates habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify curienite?+

Mohs hardness is 2. It typically shows a pearly luster. The streak is yellow. Common colors include yellow, orange-yellow.

Where is curienite found?+

Notable localities include Mounana Mine, Gabon; Sierra de Alcaraz, Spain; Utah, USA.

How much is curienite worth?+

Typical asking prices fall in the range of $50-500 depending on specimen size and matrix quality. Quality, size, and provenance can move individual specimens well outside that range.

Is curienite safe to handle?+

This mineral is radioactive. It contains toxic constituents. Contains uranium and lead; handle with care using gloves, avoid inhalation of dust, and store in a lead-lined container away from living areas. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like curienite?+

Curienite is most often confused with Carnotite, Tyuyamunite, Meta-autunite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with curienite?+

Curienite commonly co-occurs with Vanuralite, Francevillite, Curite, Boltwoodite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does curienite form in?+

Curienite typically forms in uranium-vanadium oxidized zones. Working float back to the host body is the standard way to chase a fresh occurrence.

What is curienite used for?+

Curienite is used in collector.

Find curienite on the map

RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.