Huemulite is a rare hydrated sodium magnesium vanadate that typically forms as bright orange efflorescent crusts on sandstone walls in mines. It is highly water-soluble, meaning it should be stored in a dry environment to prevent degradation.

Hardness

Mohs

Luster

Vitreous

Streak

Yellow

Transparency

Translucent

mineralrare

Huemulite

Hardness: 2
Luster: Vitreous
Streak: Yellow
Transparency: Translucent

Is this huemulite?

5-step field check

Run through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.

1
Test the hardness
Try to scratch huemulite with a known reference. Huemulite sits at Mohs 2 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Huemulite leaves a yellow streak.
3
Read the luster
Hold the specimen under a strong light. Huemulite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: orange, yellow-orange.
5
Look at form & habit
Crystal system: triclinic. Typical habit: fine-grained encrustations, acicular to fibrous aggregates.

Often confused with

Huemulite vs. its common look-alikes — and how to tell them apart in the field.

How to tell apart: Streak differs — Huemulite leaves yellow, Sherwoodite leaves light blue.

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Often found alongside huemulite

Minerals reported to co-occur with huemulite. Spotting these in float or country rock is a strong cue you are in the right ground.

All properties

Chemical formula: Na₄MgV₁₀O₂₈·24H₂O
Mohs hardness: 2
Density: 2.47 g/cm³
Colors: Orange Yellow-orange
Streak: Yellow
Luster: Vitreous
Transparency: Translucent
Crystal system: Triclinic
Crystal habit: Fine-grained Encrustations, Acicular to Fibrous Aggregates
Cleavage: None Observed
Rarity: Rare
Uses: Collector
Host rock: Sandstone Hosted Uranium-vanadium Deposits
Typical price: $50-300 per specimen

Where rockhounds find huemulite

Classic worldwide localities

Huemul Mine, Argentina
Colorado Plateau, USA

Field-hunting tip

Look in sandstone hosted uranium-vanadium deposits country — that is the host setting where huemulite typically forms. If you start seeing gypsum, vanadinite, carnotite in float, you are in the right ground. Field specimens usually show a fine-grained encrustations, acicular to fibrous aggregates habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify huemulite?+

Mohs hardness is 2. It typically shows a vitreous luster. The streak is yellow. Common colors include orange, yellow-orange.

Where is huemulite found?+

Notable localities include Huemul Mine, Argentina; Colorado Plateau, USA.

How much is huemulite worth?+

Typical asking prices fall in the range of $50-300 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

Is huemulite safe to handle?+

It contains toxic constituents. Contains vanadium, which can be toxic if ingested or inhaled as dust; wash hands thoroughly after handling and avoid creating dust. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like huemulite?+

Huemulite is most often confused with Pascoite, Sherwoodite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with huemulite?+

Huemulite commonly co-occurs with gypsum, vanadinite, carnotite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does huemulite form in?+

Huemulite typically forms in sandstone hosted uranium-vanadium deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is huemulite used for?+

Huemulite is used in collector.

Find huemulite on the map

RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.