Bauranoite is an extremely rare barium-uranium silicate mineral typically found as earthy, reddish brown crusts in oxidized zones of uranium deposits. Due to its radioactive and chemically toxic nature, it is strictly a specimen for advanced mineral collectors who understand specialized handling protocols for radioactive materials.
Is this bauranoite?
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 bauranoite with a known reference. Bauranoite sits at Mohs 5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: yellow.
- 3Read the lusterHold the specimen under a strong light. Luster: dull.
- 4Match the color rangeCompare against the expected color range: reddish brown.
- 5Look at form & habitCrystal system: triclinic. Typical habit: massive.
Often confused with
Bauranoite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Bauranoite is noticeably harder (Mohs 5 vs. 2.5); streak differs, so Bauranoite leaves yellow, Uranophane leaves yellowish white; luster reads dull on Bauranoite and vitreous on Uranophane.
How to tell apart: Bauranoite is noticeably harder (Mohs 5 vs. 3.5-4); streak differs, so Bauranoite leaves yellow, Boltwoodite leaves white; luster reads dull on Bauranoite and pearly; radial aggregates vitreous to silky; dull to earthy in microcrystalline pseudomorphs on Boltwoodite.
How to tell apart: Bauranoite is noticeably harder (Mohs 5 vs. 4); streak differs, so Bauranoite leaves yellow, Cuprosklodowskite leaves greenish yellow.
Often found alongside bauranoite
Minerals reported to co-occur with bauranoite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- BaU₂O₇·4-5H₂O
- Mohs hardness
- 5
- Density
- 5.28-5.42 g/cm³
- Colors
- Streak
- Yellow
- Luster
- Dull
- Transparency
- Semitransparent
- Crystal system
- Triclinic
- Crystal habit
- Massive
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In the oxidation zone of a U-Mo deposit, replacing "pitchblende" and replaced by uranophane
Where rockhounds find bauranoite
Classic worldwide localities
- U-Mo deposit in Russia (type locality)
Field-hunting tip
Where it forms: In the oxidation zone of a U-Mo deposit, replacing "pitchblende" and replaced by uranophane. If you start seeing uraninite, uranophane, calciouranoite in float, you are in the right ground. Typical habit: massive. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify bauranoite?+
Where is bauranoite found?+
Is bauranoite safe to handle?+
What rocks look like bauranoite?+
What minerals are found with bauranoite?+
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What is bauranoite used for?+
Find bauranoite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
