Joliotite is a rare secondary uranium carbonate mineral typically found as thin, earthy crusts or powdery coatings in oxidized uranium-bearing deposits. It is best identified by its bright yellow color and association with other secondary uranium species, though it is often difficult to distinguish from other similar uranyl minerals without X-ray diffraction. Collectors should take extreme care when handling due to its radioactive nature.
Is this joliotite?
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 joliotite with a known reference. Joliotite 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. Joliotite leaves a yellow streak.
- 3Read the lusterHold the specimen under a strong light. Joliotite typically shows a dull luster.
- 4Match the color rangeCompare against the expected color range: yellow, orange-yellow.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: crusts, earthy, powdery aggregates.
Often confused with
Joliotite vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Streak differs — Joliotite leaves yellow, Urancalcarite leaves light yellow; luster reads dull on Joliotite and pearly on Urancalcarite.
How to tell apart: Streak differs — Joliotite leaves yellow, Autunite leaves pale yellow; luster reads dull on Joliotite and pearly on Autunite.
How to tell apart: Streak differs — Joliotite leaves yellow, Zellerite leaves white; luster reads dull on Joliotite and earthy on Zellerite.
Often found alongside joliotite
Minerals reported to co-occur with joliotite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- UO₂(CO₃)·nH₂O
- Mohs hardness
- 2
- Density
- 3.5 g/cm³
- Colors
- Streak
- Yellow
- Luster
- Dull
- Transparency
- Opaque
- Crystal system
- Orthorhombic
- Crystal habit
- Crusts, Earthy, Powdery Aggregates
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Oxidized Zones of Uranium Deposits
- Typical price
- $50-300 per specimen
Where rockhounds find joliotite
Classic worldwide localities
- Jachymov, Czech Republic
- Lodève, France
- Moab, Utah, USA
Field-hunting tip
Look in oxidized zones of uranium deposits country — that is the host setting where joliotite typically forms. If you start seeing uraninite, becquerelite, calcite in float, you are in the right ground. Field specimens usually show a crusts, earthy, powdery aggregates habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify joliotite?+
Where is joliotite found?+
How much is joliotite worth?+
Is joliotite safe to handle?+
What rocks look like joliotite?+
What minerals are found with joliotite?+
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Find joliotite on the map
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