Mundite is a rare secondary uranium phosphate mineral that typically forms as a crust or small platy crystals. It is almost exclusively found in the weathered zones of granitic pegmatites, specifically documented in the Democratic Republic of the Congo. Collectors should look for its characteristic yellowish, earthy appearance alongside other uranium secondary species.

Hardness

Mohs

Luster

Dull

Streak

Yellow

Transparency

Opaque

mineralrare

Mundite

Hardness: 3
Luster: Dull
Streak: Yellow
Transparency: Opaque

Is this mundite?

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 mundite with a known reference. Mundite sits at Mohs 3 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Mundite leaves a yellow streak.
3
Read the luster
Hold the specimen under a strong light. Mundite typically shows a dull luster.
4
Match the color range
Compare against the expected color range: yellow, brownish-yellow.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: platy crystals, granular aggregates.

Often confused with

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

mineral

Meta-autunite

Mohs 2-2.5

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

How to tell apart: Luster reads dull on Mundite and earthy on Phosphuranylite.

Compare →

Often found alongside mundite

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

All properties

Chemical formula: Al(UO₂)₃(PO₄)₂(OH)₃·5.5H₂O
Mohs hardness: 3
Density: 4.2 g/cm³
Colors: Yellow Brownish-yellow
Streak: Yellow
Luster: Dull
Transparency: Opaque
Crystal system: Monoclinic
Crystal habit: Platy Crystals, Granular Aggregates
Cleavage: Perfect
Rarity: Rare
Uses: Collector
Host rock: Granite Pegmatites
Typical price: $50-300 per specimen depending on size and rarity

Where rockhounds find mundite

Classic worldwide localities

Kobokobo pegmatite, Democratic Republic of the Congo

Field-hunting tip

Look in granite pegmatites country — that is the host setting where mundite typically forms. If you start seeing meta-autunite, phuralumite, upalite in float, you are in the right ground. Field specimens usually show a platy crystals, granular aggregates habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify mundite?+

Mohs hardness is 3. It typically shows a dull luster. The streak is yellow. Common colors include yellow, brownish-yellow.

Where is mundite found?+

Notable localities include Kobokobo pegmatite, Democratic Republic of the Congo.

How much is mundite worth?+

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

Is mundite safe to handle?+

This mineral is radioactive. It contains toxic constituents. Mundite is a uranium-bearing mineral and is radioactive; it should be handled with care and stored in a sealed, labeled container in a well-ventilated area. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like mundite?+

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

What minerals are found with mundite?+

Mundite commonly co-occurs with Meta-autunite, Phuralumite, Upalite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does mundite form in?+

Mundite typically forms in granite pegmatites. Working float back to the host body is the standard way to chase a fresh occurrence.

What is mundite used for?+

Mundite is used in collector.

Find mundite on the map

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