Metazellerite is a rare uranyl carbonate mineral typically found as a dehydration product of zellerite. It is prized by collectors for its vibrant yellow-green fluorescence under ultraviolet light and often occurs as delicate, radiating needles or fibrous crusts on sandstone matrix.
Is this metazellerite?
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 metazellerite with a known reference. Metazellerite 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 white.
- 3Read the lusterHold the specimen under a strong light. Luster: chalky.
- 4Match the color rangeCompare against the expected color range: light yellow.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: fibrous, acicular, radiating sprays.
Often confused with
Metazellerite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Metazellerite leaves yellow white, Zellerite leaves white; luster reads chalky on Metazellerite and earthy on Zellerite.
How to tell apart: Luster reads chalky on Metazellerite and vitreous to pearly on cleavages on Liebigite.
Often found alongside metazellerite
Minerals reported to co-occur with metazellerite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ca(UO₂)(CO₃)₂·3H₂O
- Mohs hardness
- 2
- Density
- 3.414 g/cm³
- Colors
- Streak
- Yellow white
- Luster
- Chalky
- Transparency
- Translucent
- Crystal system
- Orthorhombic
- Crystal habit
- Fibrous, acicular, radiating sprays
- Cleavage
- Good
- Fluorescence
- Bright yellow-green under UV
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A dehydration product of zellerite
Where rockhounds find metazellerite
Classic worldwide localities
- Lucky Mc mine, Wind River Basin, Fremont Co., Wyoming, USA
- White Canyon # 1 mine, Frey Point, San Juan Co., Colorado, USA
- Jáchymov (Joachimsthal), Czech Republic
Field-hunting tip
Where it forms: A dehydration product of zellerite. If you start seeing zellerite, gypsum, limonite in float, you are in the right ground. Typical habit: fibrous, acicular, radiating sprays. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify metazellerite?+
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Is metazellerite safe to handle?+
What rocks look like metazellerite?+
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Find metazellerite on the map
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