Sabugalite is a rare secondary uranium phosphate mineral occurring as thin, fragile, lemon-yellow tabular crystals. It is typically found in the oxidation zones of uranium-rich hydrothermal deposits and is noted for its strong green fluorescence under ultraviolet radiation.
Is this sabugalite?
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 sabugalite with a known reference. Sabugalite 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: yellow white.
- 3Read the lusterHold the specimen under a strong light. Luster: weakly vitreous.
- 4Match the color rangeCompare against the expected color range: light yellow, lemon.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: thin tabular crystals, lamellar aggregates.
Often confused with
Sabugalite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Sabugalite leaves yellow white, Autunite leaves pale yellow; luster reads weakly vitreous on Sabugalite and vitreous, pearly on {001} on Autunite.
How to tell apart: Luster reads weakly vitreous on Sabugalite and pearly to dull on Meta-autunite.
Often found alongside sabugalite
Minerals reported to co-occur with sabugalite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- HAl(UO₂)₄(PO₄)₄·16H₂O
- Mohs hardness
- 2.5
- Density
- 3.2 g/cm³
- Colors
- Streak
- Yellow white
- Luster
- Weakly vitreous
- Transparency
- Transparent to translucent
- Crystal system
- Monoclinic
- Crystal habit
- Thin tabular crystals, lamellar aggregates
- Cleavage
- On {001}, perfect
- Fluorescence
- Lemon-yellow under SW and LW UV
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A secondary mineral formed in the oxidized zone of uranium veins
Where rockhounds find sabugalite
Classic worldwide localities
- Black Water mine, Black Mesa Basin, Apache Co., and at the Huskon and Arrowhead claims, Huskon district, near Cameron, Coconino Co., Arizona, USA
- Union Carbide mine, Maybell district, Moffat Co., at the Pitch mine, Marshall Pass district, Saguache Co., and the High Park claims, Teller Co., Colorado, USA
- Happy Jack mine, White Canyon, San Juan Co., Utah, USA
- Lucky Mc No. 20 mine, the Blue Buck claim and Blarco group, Fremont Co., the Poison Creek claim, Crook Co., and the Del Linch claim, Johnson Co., Wyoming, USA
- Beira Alta, from the Quarta Feira and Coitos mines, Sabugal Co., Portugal
- Kariz, Minho Province, Portugal
Field-hunting tip
Where it forms: A secondary mineral formed in the oxidized zone of uranium veins. If you start seeing meta-autunite, saléeite, phosphuranylite in float, you are in the right ground. Typical habit: thin tabular crystals, lamellar aggregates. Train your eye for that shape before scanning the outcrop.
Common questions
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Find sabugalite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
