Pandoraite-Ca is a rare vanadate mineral that typically forms as delicate, dark blue platy crystals or scales on sandstone surfaces. It is primarily found in the secondary oxidation zones of vanadium-bearing uranium deposits in the Colorado Plateau region. Due to its scarcity and fragile nature, it is a highly sought-after specimen for advanced mineral collectors.
Is this pandoraite-ca?
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 pandoraite-ca with a known reference. Pandoraite-Ca 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: light greenish blue.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: dark blue.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: platy crystals, scales.
Often confused with
Pandoraite-Ca vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Pandoraite-Ca leaves light greenish blue, Gypsum leaves white; luster reads vitreous on Pandoraite-Ca and subvitreous, pearly on {010} cleavages, silky if fibrous on Gypsum.
How to tell apart: Streak differs, so Pandoraite-Ca leaves light greenish blue, Carnotite leaves strontian-yellow; luster reads vitreous on Pandoraite-Ca and dull, earthy; silky when crystalline on Carnotite.
Often found alongside pandoraite-ca
Minerals reported to co-occur with pandoraite-ca. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- CaV₅V₂O₁₆(H₂O)₃
- Mohs hardness
- ~2.5
- Density
- 2.91 g/cm³
- Colors
- Streak
- Light greenish blue
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Platy crystals, scales
- Cleavage
- Perfect on {001}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Deposited from solutions rich in U and V where they encountered pockets of strongly reducing solutions developed around accumulations of carbonaceous plant material
Where rockhounds find pandoraite-ca
Classic worldwide localities
- Pandora mine, La Sal district (Paradox Valley district), San Juan County, Colorado, USA
Field-hunting tip
Where it forms: Deposited from solutions rich in U and V where they encountered pockets of strongly reducing solutions developed around accumulations of carbonaceous plant material. If you start seeing finchite in float, you are in the right ground. Typical habit: platy crystals, scales. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify pandoraite-ca?+
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What rocks look like pandoraite-ca?+
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Find pandoraite-ca on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
