Margaritasite is a rare cesium-bearing uranyl vanadate mineral that typically forms vibrant yellow crystalline crusts or small platy crystals. It is primarily found in the oxidized zones of uranium-vanadium deposits and is highly prized by advanced radioactive mineral collectors. Due to its radioactive nature, it requires careful storage and handling protocols.
Is this margaritasite?
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 margaritasite with a known reference. Margaritasite sits at Mohs 2-3 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Margaritasite leaves a yellow streak.
- 3Read the lusterHold the specimen under a strong light. Margaritasite typically shows a pearly luster.
- 4Match the color rangeCompare against the expected color range: yellow, golden yellow.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: platy crystals, crusts, coatings.
Often confused with
Margaritasite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside margaritasite
Minerals reported to co-occur with margaritasite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Cs,K,H₃O)₂(UO₂)₂(V₂O₈)·nH₂O
- Mohs hardness
- 2-3
- Density
- 4.15 g/cm³
- Colors
- Streak
- Yellow
- Luster
- Pearly
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Platy Crystals, Crusts, Coatings
- Cleavage
- Perfect
- Fluorescence
- Bright Yellow-green Under UV
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Oxidized Zones of Uranium-vanadium Deposits
- Typical price
- $100-500 depending on specimen size and matrix
Where rockhounds find margaritasite
Classic worldwide localities
- Mexico
- USA
Field-hunting tip
Look in oxidized zones of uranium-vanadium deposits country — that is the host setting where margaritasite typically forms. If you start seeing uraninite, carnotite, tyuyamunite in float, you are in the right ground. Field specimens usually show a platy crystals, crusts, coatings habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify margaritasite?+
Where is margaritasite found?+
How much is margaritasite worth?+
Is margaritasite safe to handle?+
What rocks look like margaritasite?+
What minerals are found with margaritasite?+
What kind of rock does margaritasite form in?+
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Find margaritasite on the map
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