Heisenbergite is a secondary uranium mineral characterized by its distinctive yellow color and platy, micaceous habit. It is found in the oxidized zones of uranium-rich ore deposits and is highly prized by collectors for its strong fluorescence under ultraviolet light.

Hardness

Mohs

Luster

Vitreous

Streak

Yellow

Transparency

Opaque to translucent

mineralrare

Heisenbergite

Hardness: ~2
Luster: Vitreous
Streak: Yellow
Transparency: Opaque to translucent

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Is this heisenbergite?

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 heisenbergite with a known reference. Heisenbergite 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. Streak: yellow.
3
Read the luster
Hold the specimen under a strong light. Luster: vitreous.
4
Match the color range
Compare against the expected color range: yellow, yellow-brown, orange-brown.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: platy or micaceous aggregates.

Often confused with

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

mineral

Autunite

Mohs 2-2.5

How to tell apart: Streak differs, so Heisenbergite leaves yellow, Autunite leaves pale yellow.

How to tell apart: Luster reads vitreous on Heisenbergite and pearly to dull on Meta-autunite.

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Often found alongside heisenbergite

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

All properties

Chemical formula: UO₂(OH)₂·H₂O
Mohs hardness: ~2
Density: 5.14 g/cm³
Colors: Yellow Yellow-brown Orange-brown
Streak: Yellow
Luster: Vitreous
Transparency: Opaque to translucent
Crystal system: Orthorhombic
Crystal habit: Platy or micaceous aggregates
Cleavage: None
Fluorescence: Bright green under UV light
Rarity: Rare
Uses: Collector
Host rock: A secondary mineral formed by weathering

Where rockhounds find heisenbergite

Classic worldwide localities

Joachimsthal, Czech Republic
Shinkolobwe, Democratic Republic of the Congo
Great Bear Lake, Canada

Field-hunting tip

Where it forms: A secondary mineral formed by weathering. If you start seeing quartz, uraninite, billietite in float, you are in the right ground. Typical habit: platy or micaceous aggregates. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify heisenbergite?+

Mohs hardness is ~2. Luster: vitreous. The streak is yellow. Common colors include yellow, yellow-brown, orange-brown.

Where is heisenbergite found?+

Notable localities include Joachimsthal, Czech Republic; Shinkolobwe, Democratic Republic of the Congo; Great Bear Lake, Canada.

Is heisenbergite safe to handle?+

Heisenbergite contains uranium or thorium and calls for real care. This mineral is both radioactive and toxic due to its uranium content. Handle with gloves, keep in a sealed container, and wash hands thoroughly after contact; avoid inhaling dust.

What rocks look like heisenbergite?+

Heisenbergite is most often confused with Autunite, Meta-autunite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with heisenbergite?+

Heisenbergite commonly co-occurs with Quartz, Uraninite, Billietite, Studtite, Rutherfordine, Joliotite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does heisenbergite form in?+

Where it forms: A secondary mineral formed by weathering. Working float back to the host body is the standard way to chase a fresh occurrence.

What is heisenbergite used for?+

Heisenbergite is used in collector.

Find heisenbergite on the map

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