Paddlewheelite is a very rare uranyl carbonate mineral typically found as small, blue-green platy crystals or crusts. It is named for its unique crystal structure that resembles a paddlewheel. It is predominantly found in the historic mining district of Jáchymov, Czech Republic, associated with other secondary uranium minerals.
Is this paddlewheelite?
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 paddlewheelite with a known reference. Paddlewheelite 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. Paddlewheelite leaves a very pale blue-green streak.
- 3Read the lusterHold the specimen under a strong light. Paddlewheelite typically shows a adamantine luster.
- 4Match the color rangeCompare against the expected color range: blue-green.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: platy crystals, crusts.
Often confused with
Paddlewheelite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Paddlewheelite leaves very pale blue-green, Liebigite leaves pale yellow; luster reads adamantine on Paddlewheelite and vitreous on Liebigite.
How to tell apart: Streak differs, so Paddlewheelite leaves very pale blue-green, Andersonite leaves white; luster reads adamantine on Paddlewheelite and vitreous on Andersonite.
Often found alongside paddlewheelite
Minerals reported to co-occur with paddlewheelite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- MgCu₂(UO₂)₂(CO₃)₃(OH)₄·18H₂O
- Mohs hardness
- 2
- Density
- 2.5 g/cm³
- Colors
- Streak
- Very Pale Blue-green
- Luster
- Adamantine
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Platy Crystals, Crusts
- Cleavage
- Perfect
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Hydrothermal Veins
Where rockhounds find paddlewheelite
Classic worldwide localities
- Jáchymov, Czech Republic
Field-hunting tip
Look in hydrothermal veins country, the host setting where paddlewheelite typically forms. If you start seeing uraninite, liebigite, andersonite in float, you are in the right ground. Field specimens usually show a platy crystals, crusts habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify paddlewheelite?+
Where is paddlewheelite found?+
Is paddlewheelite safe to handle?+
What rocks look like paddlewheelite?+
What minerals are found with paddlewheelite?+
What kind of rock does paddlewheelite form in?+
What is paddlewheelite used for?+
Find paddlewheelite on the map
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