Hughesite is a rare hydrated sodium aluminum vanadate mineral that typically forms as small, bright yellow to greenish-orange to golden orange prismatic crystals. It is primarily found in the oxidized zones of vanadium-rich sandstone deposits, often occurring as crusts or tiny groupings within mine workings in the Colorado Plateau.
Is this hughesite?
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 hughesite with a known reference. Hughesite sits at Mohs 1, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: yellow.
- 3Read the lusterHold the specimen under a strong light. Luster: subadamantine.
- 4Match the color rangeCompare against the expected color range: orange, golden orange.
- 5Look at form & habitCrystal system: triclinic. Typical habit: prismatic to acicular crystals.
Often confused with
Hughesite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Pascoite is the harder of the two (Mohs ~2.5 vs. 1); streak differs, so Hughesite leaves yellow, Pascoite leaves cadmium-yellow; luster reads subadamantine on Hughesite and vitreous to subadamantine on Pascoite.
How to tell apart: Streak differs, so Hughesite leaves yellow, Hewettite leaves brownish red; luster reads subadamantine on Hughesite and silky to adamantine on Hewettite.
Often found alongside hughesite
Minerals reported to co-occur with hughesite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Na₃Al[V₁₀O₂₈]·22H₂O
- Mohs hardness
- 1
- Density
- 2.29 g/cm³
- Colors
- OrangeGolden orange
- Streak
- Yellow
- Luster
- Subadamantine
- Transparency
- Transparent to translucent
- Crystal system
- Triclinic
- Crystal habit
- Prismatic to acicular crystals
- Cleavage
- Perfect on (001)
- Rarity
- Rare
- Uses
- Collector
- Host rock
- vanadium-uranium sandstone deposits
Where rockhounds find hughesite
Classic worldwide localities
- Sunday mine, Gypsum Valley, San Miguel County, Slick Rock District, Colorado, USA
Field-hunting tip
Where it forms: vanadium-uranium sandstone deposits. If you start seeing rossite, lasalite, hewettite in float, you are in the right ground. Typical habit: prismatic to acicular crystals. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify hughesite?+
Where is hughesite found?+
Is hughesite safe to handle?+
What rocks look like hughesite?+
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Find hughesite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
