Pascoite is a rare secondary vanadium mineral that typically forms as bright orange, tabular crystals or efflorescent crusts in arid uranium-vanadium mining districts. It is highly soluble in water and often found as a post-mining alteration product on sandstone walls, requiring protection from high humidity to prevent dehydration.
Is this pascoite?
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 pascoite with a known reference. Pascoite sits at Mohs 2 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Pascoite leaves a yellow streak.
- 3Read the lusterHold the specimen under a strong light. Pascoite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: orange, red-orange, yellow-orange.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: tabular crystals, crusts, or efflorescent coatings.
Often confused with
Pascoite vs. its common look-alikes — and how to tell them apart in the field.

How to tell apart: Luster reads vitreous on Pascoite and dull on Carnotite.

How to tell apart: Luster reads vitreous on Pascoite and pearly on Tyuyamunite.

How to tell apart: Pascoite is noticeably harder (Mohs 2 vs. approx 1); streak differs — Pascoite leaves yellow, Hewettite leaves brownish red; luster reads vitreous on Pascoite and pearly on Hewettite.
Often found alongside pascoite
Minerals reported to co-occur with pascoite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ca₃V₁₀O₂₈·17H₂O
- Mohs hardness
- 2
- Density
- 2.8 g/cm³
- Streak
- Yellow
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Tabular Crystals, Crusts, Or Efflorescent Coatings
- Cleavage
- Perfect On {001}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Vanadium-uranium Sandstone Deposits
- Typical price
- $20-150 per specimen depending on size and quality
Where rockhounds find pascoite
Classic worldwide localities
- Minerva No. 1 mine, Utah, USA
- Jo Dandy mine, Colorado, USA
- Rico, Colorado, USA
- San Rafael Swell, Utah, USA
Field-hunting tip
Look in vanadium-uranium sandstone deposits country — that is the host setting where pascoite typically forms. If you start seeing gypsum, hewettite, rossite in float, you are in the right ground. Field specimens usually show a tabular crystals, crusts, or efflorescent coatings habit, so train your eye for that shape before scanning the outcrop.



