Phosphowalpurgite is a rare secondary uranium phosphate mineral that forms as a constituent in the oxidation zones of uranium-bismuth deposits. It is best identified by its bright yellow, tabular crystal plates and association with other secondary uranium minerals. Due to its radioactive nature, it is strictly for advanced mineral collectors who understand proper safety and storage protocols.
Is this phosphowalpurgite?
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 phosphowalpurgite with a known reference. Phosphowalpurgite sits at Mohs 3.5 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Phosphowalpurgite leaves a pale yellow streak.
- 3Read the lusterHold the specimen under a strong light. Phosphowalpurgite typically shows a adamantine luster.
- 4Match the color rangeCompare against the expected color range: yellow, yellow-orange.
- 5Look at form & habitCrystal system: triclinic. Typical habit: platy crystals, tabular aggregates.
Often confused with
Phosphowalpurgite vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Streak differs — Phosphowalpurgite leaves pale yellow, Walpurgite leaves yellowish.
How to tell apart: Phosphowalpurgite is noticeably harder (Mohs 3.5 vs. 2-2.5); streak differs — Phosphowalpurgite leaves pale yellow, Torbernite leaves pale green; luster reads adamantine on Phosphowalpurgite and vitreous on Torbernite.
Often found alongside phosphowalpurgite
Minerals reported to co-occur with phosphowalpurgite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (UO₂)(BiO)₄(PO₄)₂(OH)₂·3H₂O
- Mohs hardness
- 3.5
- Density
- 5.68 g/cm³
- Colors
- Streak
- Pale Yellow
- Luster
- Adamantine
- Transparency
- Transparent
- Crystal system
- Triclinic
- Crystal habit
- Platy Crystals, Tabular Aggregates
- Cleavage
- Perfect On {001}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Hydrothermal Veins Associated with Bismuth and Uranium Deposits
- Typical price
- $100-500 per specimen
Where rockhounds find phosphowalpurgite
Classic worldwide localities
- Wittichen, Germany
- Schneeberg, Germany
- Jáchymov, Czech Republic
Field-hunting tip
Look in hydrothermal veins associated with bismuth and uranium deposits country — that is the host setting where phosphowalpurgite typically forms. If you start seeing bismutite, uraninite, pucherite in float, you are in the right ground. Field specimens usually show a platy crystals, tabular aggregates habit, so train your eye for that shape before scanning the outcrop.
Common questions
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How much is phosphowalpurgite worth?+
Is phosphowalpurgite safe to handle?+
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Find phosphowalpurgite on the map
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