Rauchite is a rare nickel-bearing uranyl arsenate mineral characterized by its bright yellow to yellow-green, thin platy crystals. It is primarily found in old hydrothermal mining districts where primary uranium minerals have undergone oxidation. Due to its radioactivity and toxic elemental content, it is strictly a specimen for advanced collectors who follow appropriate safety protocols.
Is this rauchite?
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 rauchite with a known reference. Rauchite 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. Streak: white.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous, pearly on {001}.
- 4Match the color rangeCompare against the expected color range: yellow, yellow-green.
- 5Look at form & habitCrystal system: triclinic. Typical habit: platy or micaceous crystals.
Often confused with
Rauchite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Rauchite leaves white, Meta-autunite leaves yellow; luster reads vitreous, pearly on {001} on Rauchite and pearly to dull on Meta-autunite.
How to tell apart: Streak differs, so Rauchite leaves white, Torbernite leaves pale green.
Often found alongside rauchite
Minerals reported to co-occur with rauchite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ni(UO₂)₂(AsO₄)₂·10H₂O
- Mohs hardness
- ~2
- Density
- 3.427 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous, pearly on {001}
- Transparency
- Transparent to translucent
- Crystal system
- Triclinic
- Crystal habit
- Platy or micaceous crystals
- Cleavage
- Perfect on {001}
- Fluorescence
- Bright green under UV light
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A secondary mineral found in small cavities and cracks in slightly oxidized uraninite-bearing dolomite veins
Where rockhounds find rauchite
Classic worldwide localities
- Adygea Republic, Northern Caucasus, Russia
Field-hunting tip
Where it forms: A secondary mineral found in small cavities and cracks in slightly oxidized uraninite-bearing dolomite veins. If you start seeing dymkovite, uraninite, nickeline in float, you are in the right ground. Typical habit: platy or micaceous crystals. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify rauchite?+
Where is rauchite found?+
Is rauchite safe to handle?+
What rocks look like rauchite?+
What minerals are found with rauchite?+
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What is rauchite used for?+
Find rauchite on the map
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