Metasaléeite is a rare secondary uranium mineral that forms through the dehydration of saléeite. Collectors should look for thin, yellow, micaceous tabular crystals often found as crusts on rock surfaces in uranium-rich deposits.
Is this metasaléeite?
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 metasaléeite with a known reference. Metasaléeite 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: pearly.
- 4Match the color rangeCompare against the expected color range: yellow, yellow-green.
- 5Look at form & habitCrystal system: tetragonal. Typical habit: tabular crystals, micaceous aggregates, crusts.
Often confused with
Metasaléeite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Luster reads pearly on Metasaléeite and vitreous, pearly on {001} on Autunite.
How to tell apart: Luster reads pearly on Metasaléeite and vitreous, subadamantine, waxy, pearly on cleavages; becoming dull on dehydration to metatorbernite on Torbernite.
How to tell apart: Streak differs, so Metasaléeite leaves pale yellow, Meta-autunite leaves yellow.
Often found alongside metasaléeite
Minerals reported to co-occur with metasaléeite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Mg(UO₂)₂(PO₄)₂·8H₂O
- Mohs hardness
- 2.5
- Colors
- Streak
- Pale yellow
- Luster
- Pearly
- Transparency
- Translucent
- Crystal system
- Tetragonal
- Crystal habit
- Tabular crystals, micaceous aggregates, crusts
- Cleavage
- Perfect basal
- Fluorescence
- Bright yellow-green under UV
- Rarity
- Rare
- Uses
- Collector, Scientific research
- Host rock
- oxidized zones of uranium-bearing hydrothermal veins
Where rockhounds find metasaléeite
Classic worldwide localities
- Salée mine, France
- Margnac mine, France
- Lodève, France
- Wheal Basset, UK
Field-hunting tip
Where it forms: oxidized zones of uranium-bearing hydrothermal veins. If you start seeing uraninite, gummite, pyrite in float, you are in the right ground. Typical habit: tabular crystals, micaceous aggregates, crusts. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify metasaléeite?+
Where is metasaléeite found?+
Is metasaléeite safe to handle?+
What rocks look like metasaléeite?+
What minerals are found with metasaléeite?+
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Find metasaléeite on the map
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