Caseyite is a rare secondary mineral found in oxidized vanadium-uranium deposits. It typically occurs as small, delicate, yellow platy crystals or thin crusts in sandstone cavities.
Is this caseyite?
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 caseyite with a known reference. Caseyite sits at Mohs 2-3, 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: vitreous.
- 4Match the color rangeCompare against the expected color range: yellow.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: platy crystals, crusts.
Often confused with
Caseyite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Caseyite is noticeably harder (Mohs 2-3 vs. ~1); streak differs, so Caseyite leaves pale yellow, Hewettite leaves brownish red; luster reads vitreous on Caseyite and silky to adamantine on Hewettite.
How to tell apart: Streak differs, so Caseyite leaves pale yellow, Metahewettite leaves maroon to brownish red; luster reads vitreous on Caseyite and dull to somewhat silky on Metahewettite.
Often found alongside caseyite
Minerals reported to co-occur with caseyite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- [(VO₂)Al₇.₅(OH)₁₅(H₂O)₁₃]₂[H₂VV₉O₂₈][V₁₀O₂₈]₂·90H₂O
- Mohs hardness
- 2-3
- Density
- 2.151 g/cm³
- Colors
- Streak
- Pale yellow
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Platy crystals, crusts
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- sandstone cavities
Where rockhounds find caseyite
Classic worldwide localities
- Temple Mountain, Emery County, Utah, USA
Field-hunting tip
Where it forms: sandstone cavities. If you start seeing gypsum, barite, huemulite in float, you are in the right ground. Typical habit: platy crystals, crusts. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify caseyite?+
Where is caseyite found?+
Is caseyite safe to handle?+
What rocks look like caseyite?+
What minerals are found with caseyite?+
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What is caseyite used for?+
Find caseyite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
