Chalcolite, more commonly known as Torbernite, is a striking bright green secondary uranium mineral. It is highly prized by collectors for its brilliant color and perfect micaceous crystal habit, though it requires careful storage and handling due to its radioactivity.

Hardness

2-2.5

Mohs

Luster

Pearly

Streak

Pale green

Transparency

Transparent

mineraluncommonAutunite Group family

Chalcolite

Hardness: 2-2.5
Luster: Pearly
Streak: Pale green
Transparency: Transparent

Is this chalcolite?

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 chalcolite with a known reference. Chalcolite sits at Mohs 2-2.5, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: pale green.
3
Read the luster
Hold the specimen under a strong light. Luster: pearly.
4
Match the color range
Compare against the expected color range: emerald green, grass green, leaf green.
5
Look at form & habit
Crystal system: tetragonal. Typical habit: tabular crystals, micaceous, foliated, encrustations.

Often confused with

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

mineral

Autunite

Mohs 2-2.5

How to tell apart: Luster reads pearly on Chalcolite and vitreous, pearly on {001} on Autunite.

Compare →

Often found alongside chalcolite

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

All properties

Chemical formula: Cu(UO₂)₂(PO₄)₂·8-12H₂O
Mohs hardness: 2-2.5
Density: 3.22 g/cm³
Colors: Emerald green Grass greenLeaf green
Streak: Pale green
Luster: Pearly
Transparency: Transparent
Crystal system: Tetragonal
Crystal habit: Tabular crystals, micaceous, foliated, encrustations
Cleavage: Perfect basal
Rarity: Uncommon
Uses: Collector
Host rock: oxidized zones of uranium deposits

Where rockhounds find chalcolite

1 mapped spots

Classic worldwide localities

Cornwall, England
Katanga, Democratic Republic of the Congo
Musonoi Mine, Congo
Schneeberg, Germany

Field-hunting tip

Where it forms: oxidized zones of uranium deposits. If you start seeing autunite, uraninite, goethite in float, you are in the right ground. Typical habit: tabular crystals, micaceous, foliated, encrustations. Train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Oregon. Start trip planning there.

Browse 1 U.S. spots for chalcolite →

More chalcolite photos

Common questions

How do you identify chalcolite?+

Mohs hardness is 2-2.5. Luster: pearly. The streak is pale green. Common colors include emerald green, grass green, leaf green.

Where is chalcolite found?+

Notable localities include Cornwall, England; Katanga, Democratic Republic of the Congo; Musonoi Mine, Congo; Schneeberg, Germany.

Can I find chalcolite in the United States?+

RockHoundR maps 1 chalcolite rockhounding spots across 1 U.S. states. The top states are Oregon.

Is chalcolite safe to handle?+

Chalcolite contains copper and uranium or thorium and calls for real care. This mineral is radioactive and contains copper and uranium. Always handle with gloves, avoid inhaling dust, store in a lead-lined container away from living areas, and wash hands thoroughly after contact.

What rocks look like chalcolite?+

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

What minerals are found with chalcolite?+

Chalcolite commonly co-occurs with Autunite, Uraninite, Goethite, Malachite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does chalcolite form in?+

Where it forms: oxidized zones of uranium deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is chalcolite used for?+

Chalcolite is used in collector.

Find chalcolite on the map

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