Wyartite is a very rare secondary uranium mineral typically found as small, vibrant green prismatic to acicular crystal sprays. It is almost exclusively found in association with other complex uranium oxides and carbonates in the oxidation zones of uranium-rich ore bodies.
Is this wyartite?
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 wyartite with a known reference. Wyartite sits at Mohs 3-4, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: brownish violet.
- 3Read the lusterHold the specimen under a strong light. Luster: dull, vitreous to submetallic on cleavages.
- 4Match the color rangeCompare against the expected color range: black, greenish black, black violet.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: platy.
Often confused with
Wyartite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Wyartite leaves brownish violet, Vandenbrandeite leaves green; luster reads dull, vitreous to submetallic on cleavages on Wyartite and vitreous on Vandenbrandeite.
How to tell apart: Streak differs, so Wyartite leaves brownish violet, Curite leaves orange; luster reads dull, vitreous to submetallic on cleavages on Wyartite and adamantine on Curite.
How to tell apart: Streak differs, so Wyartite leaves brownish violet, Becquerelite leaves yellow; luster reads dull, vitreous to submetallic on cleavages on Wyartite and adamantine to greasy on Becquerelite.
Often found alongside wyartite
Minerals reported to co-occur with wyartite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- CaU(UO₂)₂(CO₃)O₄(OH)·7H₂O
- Mohs hardness
- 3-4
- Density
- 4.69 g/cm³
- Colors
- Streak
- Brownish violet
- Luster
- Dull, vitreous to submetallic on cleavages
- Transparency
- Opaque to translucent
- Crystal system
- Orthorhombic
- Crystal habit
- Platy
- Cleavage
- On {001}, perfect; on {010}, less so
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A rare secondary mineral formed as an alteration product of uraninite in the oxide zone of a uranium deposit
Where rockhounds find wyartite
Classic worldwide localities
- Shinkolobwe, Katanga Province, Congo (Shaba Province, Zaire)
Field-hunting tip
Where it forms: A rare secondary mineral formed as an alteration product of uraninite in the oxide zone of a uranium deposit. If you start seeing wölsendorfite, rutherfordine, uranophane in float, you are in the right ground. Typical habit: platy. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify wyartite?+
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Find wyartite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
