Deliensite is a rare secondary uranium mineral that forms thin, platy, pearly yellow crystals in the oxidized zones of uranium deposits. It is primarily known for its association with other secondary uranyl minerals found at the Shinkolobwe mine.
Is this deliensite?
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 deliensite with a known reference. Deliensite 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. Streak: white.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: yellow, white, grayish.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: aggregates, spherical.
Often confused with
Deliensite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Deliensite leaves white, Uranopilite leaves pale yellow; luster reads vitreous on Deliensite and silky on Uranopilite.
How to tell apart: Streak differs, so Deliensite leaves white, Zippeite leaves yellow white.
Often found alongside deliensite
Minerals reported to co-occur with deliensite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Fe(UO₂)₂(SO₄)₂(OH)₂·7H₂O
- Mohs hardness
- 2
- Density
- 3.268 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent to translucent
- Crystal system
- Orthorhombic
- Crystal habit
- Aggregates, spherical
- Cleavage
- On {100}, perfect; on {010}, a parting
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A rare mineral in the oxidized portions of a uranium deposit
Where rockhounds find deliensite
Classic worldwide localities
- Mas-d’Alary uranium deposit, three km south-southeast of Lodève, Hérault, France
Field-hunting tip
Where it forms: A rare mineral in the oxidized portions of a uranium deposit. If you start seeing uraninite, gypsum, pyrite in float, you are in the right ground. Typical habit: aggregates, spherical. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify deliensite?+
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Find deliensite on the map
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