Bariandite is an extremely rare vanadium oxide mineral often found as dark, botryoidal crusts or radial sprays. It is most commonly identified in vanadium deposits where it forms as a secondary mineral during the oxidation of vanadium-bearing ores.
Is this bariandite?
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 bariandite with a known reference. Bariandite 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. Streak: black.
- 3Read the lusterHold the specimen under a strong light. Luster: submetallic.
- 4Match the color rangeCompare against the expected color range: blue black.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: fibrous.
Often confused with
Bariandite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Bariandite leaves black, Corvusite leaves purplish blue-black; luster reads submetallic on Bariandite and “lusterous” on Corvusite.
How to tell apart: Bariandite is noticeably harder (Mohs 2-3 vs. ~1); streak differs, so Bariandite leaves black, Hewettite leaves brownish red; luster reads submetallic on Bariandite and silky to adamantine on Hewettite.
Often found alongside bariandite
Minerals reported to co-occur with bariandite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Al₀.₆(V⁵⁺,V⁴⁺)₈O₂₀·9H₂O
- Mohs hardness
- 2-3
- Density
- 2.7 g/cm³
- Colors
- Streak
- Black
- Luster
- Submetallic
- Transparency
- Opaque
- Crystal system
- Monoclinic
- Crystal habit
- Fibrous
- Cleavage
- {001}, perfect
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In the oxidation zone of a uranium mineral deposit (Mounana mine, Gabon); in the oxidation zone of a vanadium deposit (Minasragra, Peru)
Where rockhounds find bariandite
Classic worldwide localities
- Mounana uranium mine, Franceville, Gabon
- Minasragra, 46 km from Cerro de Pasco, Peru
Field-hunting tip
Where it forms: In the oxidation zone of a uranium mineral deposit (Mounana mine, Gabon); in the oxidation zone of a vanadium deposit (Minasragra, Peru). If you start seeing duttonite, lenoblite, roscoelite in float, you are in the right ground. Typical habit: fibrous. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify bariandite?+
Where is bariandite found?+
Is bariandite safe to handle?+
What rocks look like bariandite?+
What minerals are found with bariandite?+
What kind of rock does bariandite form in?+
What is bariandite used for?+
Find bariandite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
