Hügelite is a rare secondary lead uranyl arsenate typically occurring as small, orange-brown tabular crystals in the oxidation zones of lead-zinc deposits. It is best identified by its association with other secondary arsenates in the Tsumeb mine environment and its characteristic adamantine luster. Collectors prize it for its rarity and its distinct deep orange color saturation.
Is this hügelite?
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 hügelite with a known reference. Hügelite sits at Mohs ~2.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: pale yellow.
- 3Read the lusterHold the specimen under a strong light. Luster: greasy to adamantine.
- 4Match the color rangeCompare against the expected color range: brown, orange yellow.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: prismatic.
Often confused with
Hügelite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Hügelite leaves pale yellow, Descloizite leaves orange to brownish red.
How to tell apart: Mimetite is the harder of the two (Mohs 3.5-4 vs. ~2.5); streak differs, so Hügelite leaves pale yellow, Mimetite leaves white; luster reads greasy to adamantine on Hügelite and resinous to subadamantine on Mimetite.
How to tell apart: Duftite is the harder of the two (Mohs 4.5 vs. ~2.5); luster reads greasy to adamantine on Hügelite and dull to vitreous on fractures on Duftite.
Often found alongside hügelite
Minerals reported to co-occur with hügelite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Pb₂(UO₂)₃O₂(AsO₄)₂·5H₂O
- Mohs hardness
- ~2.5
- Density
- 5.1 g/cm³
- Colors
- Streak
- Pale yellow
- Luster
- Greasy to adamantine
- Transparency
- Transparent to translucent
- Crystal system
- Monoclinic
- Crystal habit
- Prismatic
- Cleavage
- On {100}, good; on {110}, probable
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A rare secondary mineral in cavities in hornstone breccia
Where rockhounds find hügelite
Classic worldwide localities
- Michael mine, Weiler, near Lahr, Black Forest, Germany
Field-hunting tip
Where it forms: A rare secondary mineral in cavities in hornstone breccia. If you start seeing hallimondite, widenmannite, zeunerite in float, you are in the right ground. Typical habit: prismatic. Train your eye for that shape before scanning the outcrop.
Common questions
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Is hügelite safe to handle?+
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Find hügelite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
