Cobaltzippeite is a rare secondary uranium mineral that forms in the oxidized zones of uranium-bearing deposits. Collectors prize it for its vibrant orange-red color and bright fluorescence under UV light, though its radioactivity necessitates careful handling and storage.
Is this cobaltzippeite?
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 cobaltzippeite with a known reference. Cobaltzippeite 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: yellow-orange.
- 3Read the lusterHold the specimen under a strong light. Luster: earthy.
- 4Match the color rangeCompare against the expected color range: orange, tan.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: botryoidal, encrustations.
Often confused with
Cobaltzippeite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Cobaltzippeite leaves yellow-orange, Zippeite leaves yellow white; luster reads earthy on Cobaltzippeite and vitreous on Zippeite.
How to tell apart: Streak differs, so Cobaltzippeite leaves yellow-orange, Johannite leaves pale green; luster reads earthy on Cobaltzippeite and vitreous on Johannite.
How to tell apart: Streak differs, so Cobaltzippeite leaves yellow-orange, Liebigite leaves yellow white; luster reads earthy on Cobaltzippeite and vitreous to pearly on cleavages on Liebigite.
Often found alongside cobaltzippeite
Minerals reported to co-occur with cobaltzippeite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Co(UO₂)₂(SO₄)(OH)₄·nH₂O
- Mohs hardness
- ~2
- Density
- 4.3 g/cm³
- Streak
- Yellow-orange
- Luster
- Earthy
- Transparency
- Semitransparent
- Crystal system
- Orthorhombic
- Crystal habit
- Botryoidal, encrustations
- Cleavage
- On {010}, perfect (synthetic)
- Fluorescence
- Bright yellow-green under UV light
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Rarely as efflorescences on the mine walls in oxidized portions of a uraninite deposit containing gersdorffite
Where rockhounds find cobaltzippeite
Classic worldwide localities
- Happy Jack mine, White Canyon, San Juan Co., Utah, USA
Field-hunting tip
Where it forms: Rarely as efflorescences on the mine walls in oxidized portions of a uraninite deposit containing gersdorffite. If you start seeing sodium-zippeite, uranopilite, johannite in float, you are in the right ground. Typical habit: botryoidal, encrustations. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify cobaltzippeite?+
Where is cobaltzippeite found?+
Is cobaltzippeite safe to handle?+
What rocks look like cobaltzippeite?+
What minerals are found with cobaltzippeite?+
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Find cobaltzippeite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
