Ulrichite is a rare secondary uranium mineral typically found as vibrant green, platy crystals in hydrothermal deposits. It is highly sought after by radioactive mineral collectors due to its distinct crystal form and striking color.

Hardness

~3.5

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent to translucent

mineralrare

Ulrichite

Hardness: ~3.5
Luster: Vitreous
Streak: White
Transparency: Transparent to translucent

Is this ulrichite?

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 ulrichite with a known reference. Ulrichite sits at Mohs ~3.5, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: white.
3
Read the luster
Hold the specimen under a strong light. Luster: vitreous.
4
Match the color range
Compare against the expected color range: green, lime green.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: acicular, radial.

Often confused with

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

mineral

Autunite

Mohs 2-2.5

How to tell apart: Ulrichite is noticeably harder (Mohs ~3.5 vs. 2-2.5); streak differs, so Ulrichite leaves white, Autunite leaves pale yellow.

Compare →

Often found alongside ulrichite

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

All properties

Chemical formula: CaCu(UO₂)(PO₄)₂·4H₂O
Mohs hardness: ~3.5
Density: 3.71 g/cm³
Colors: GreenLime green
Streak: White
Luster: Vitreous
Transparency: Transparent to translucent
Crystal system: Monoclinic
Crystal habit: Acicular, radial
Cleavage: Perfect
Rarity: Rare
Uses: Collector
Host rock: A secondary mineral in miarolitic cavities in pegmatoidal granite

Where rockhounds find ulrichite

Classic worldwide localities

Lake Boga granite quarry, near Swan Hill, Victoria, Australia

Field-hunting tip

Where it forms: A secondary mineral in miarolitic cavities in pegmatoidal granite. If you start seeing turquoise-chalcosiderite, cyrilovite, torbernite in float, you are in the right ground. Typical habit: acicular, radial. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify ulrichite?+

Mohs hardness is ~3.5. Luster: vitreous. The streak is white. Common colors include green, lime green.

Where is ulrichite found?+

Notable localities include Lake Boga granite quarry, near Swan Hill, Victoria, Australia.

Is ulrichite safe to handle?+

Ulrichite contains copper and uranium or thorium and calls for real care. Ulrichite is radioactive due to its uranium content and contains copper, which can be toxic if ingested or inhaled. Handle with gloves, store in a labeled lead-lined or shielded container, and wash hands thoroughly after handling.

What rocks look like ulrichite?+

Ulrichite 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 ulrichite?+

Ulrichite commonly co-occurs with Turquoise-chalcosiderite, Cyrilovite, Torbernite, Libethenite, Sampleite, Saléeite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does ulrichite form in?+

Where it forms: A secondary mineral in miarolitic cavities in pegmatoidal granite. Working float back to the host body is the standard way to chase a fresh occurrence.

What is ulrichite used for?+

Ulrichite is used in collector.

Find ulrichite on the map

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