Ludjibaite is a rare copper phosphate mineral often found as attractive, bright blue, botryoidal or spherulitic crusts in oxidized copper deposits. It is a dimorph of pseudomalachite and is primarily sought after by advanced collectors for its distinctive color and occurrence in the Katanga copper belt.

Hardness

3.5-4

Mohs

Luster

Vitreous

Streak

Pale blue to white

Transparency

Translucent to opaque

mineralrarePseudomalachite Group family

Ludjibaite

Hardness: 3.5-4
Luster: Vitreous
Streak: Pale blue to white
Transparency: Translucent to opaque

Is this ludjibaite?

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 ludjibaite with a known reference. Ludjibaite sits at Mohs 3.5-4, 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 blue to 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: blue green.
5
Look at form & habit
Crystal system: triclinic. Typical habit: botryoidal crusts, radiating aggregates, spherulitic.

Often confused with

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

How to tell apart: Streak differs, so Ludjibaite leaves pale blue to white, Libethenite leaves light green.

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Often found alongside ludjibaite

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

All properties

Chemical formula: Cu₅(PO₄)₂(OH)₄
Mohs hardness: 3.5-4
Density: 4.36 g/cm³
Colors: Blue green
Streak: Pale blue to white
Luster: Vitreous
Transparency: Translucent to opaque
Crystal system: Triclinic
Crystal habit: Botryoidal crusts, radiating aggregates, spherulitic
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: A rare mineral in the oxidized zone of some copper deposits

Where rockhounds find ludjibaite

Classic worldwide localities

Ludjiba mine, about 12 km southeast of Kambove, Katanga Province, Congo (Shaba Province, Zaire)
Lubietová, near Baňská Bystrica (Libethen, near Neusohl), Slovakia
Käusersteimel mine, near Kausen, Siegerland, Germany

Field-hunting tip

Where it forms: A rare mineral in the oxidized zone of some copper deposits. If you start seeing pseudomalachite, libethenite in float, you are in the right ground. Typical habit: botryoidal crusts, radiating aggregates, spherulitic. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify ludjibaite?+

Mohs hardness is 3.5-4. Luster: vitreous. The streak is pale blue to white. Common colors include blue green.

Where is ludjibaite found?+

Notable localities include Ludjiba mine, about 12 km southeast of Kambove, Katanga Province, Congo (Shaba Province, Zaire); Lubietová, near Baňská Bystrica (Libethen, near Neusohl), Slovakia; Käusersteimel mine, near Kausen, Siegerland, Germany.

Is ludjibaite safe to handle?+

Ludjibaite contains copper. Contains copper; wash hands thoroughly after handling and avoid inhaling dust during preparation or cleaning.

What rocks look like ludjibaite?+

Ludjibaite is most often confused with Pseudomalachite, Cornetite, Libethenite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with ludjibaite?+

Ludjibaite commonly co-occurs with Pseudomalachite, Libethenite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does ludjibaite form in?+

Where it forms: A rare mineral in the oxidized zone of some copper deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is ludjibaite used for?+

Ludjibaite is used in collector.

Find ludjibaite on the map

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