Phuralumite is a rare secondary uranium mineral that typically forms as delicate, sulfur-yellow platy crystal aggregates. It is primarily found as an oxidation product in uranium-rich pegmatites and is highly prized by collectors of radioactive minerals due to its intense yellow-green fluorescence.
Is this phuralumite?
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 phuralumite with a known reference. Phuralumite sits at Mohs ~3, 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: vitreous.
- 4Match the color rangeCompare against the expected color range: lemon.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: prismatic.
Often confused with
Phuralumite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Phuralumite leaves yellow white, Phosphuranylite leaves light yellow.
How to tell apart: Streak differs, so Phuralumite leaves yellow white, Upalite leaves light yellow; luster reads vitreous on Phuralumite and dull on Upalite.
Often found alongside phuralumite
Minerals reported to co-occur with phuralumite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Al₂[(UO₂)₃(PO₄)₂O(OH)](OH)₃(H₂O)₉
- Mohs hardness
- ~3
- Density
- 3.5 g/cm³
- Colors
- Streak
- Yellow white
- Luster
- Vitreous
- Transparency
- Semitransparent
- Crystal system
- Monoclinic
- Crystal habit
- Prismatic
- Cleavage
- On {010}, perfect
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A rare secondary mineral in the oxidized uraniferous zone of a complex granite pegmatite
Where rockhounds find phuralumite
Classic worldwide localities
- Kobokobo pegmatite, Lusungu River district, Kivu Province, Congo (Zaire)
Field-hunting tip
Where it forms: A rare secondary mineral in the oxidized uraniferous zone of a complex granite pegmatite. If you start seeing meta-autunite, phosphuranylite, threadgoldite in float, you are in the right ground. Typical habit: prismatic. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify phuralumite?+
Where is phuralumite found?+
Is phuralumite safe to handle?+
What rocks look like phuralumite?+
What minerals are found with phuralumite?+
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Find phuralumite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
