Moluranite is a rare secondary uranium-molybdenum mineral typically found as soft, yellow fibrous crusts or powdery coatings in oxidized ore zones. It is highly radioactive and primarily sought after by advanced collectors of rare uranium minerals for its distinct chemical composition.

Hardness

Mohs

Luster

Earthy

Streak

Yellow

Transparency

Opaque

mineralrare

Moluranite

Hardness: 2
Luster: Earthy
Streak: Yellow
Transparency: Opaque

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Is this moluranite?

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 moluranite with a known reference. Moluranite 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. Moluranite leaves a yellow streak.
3
Read the luster
Hold the specimen under a strong light. Moluranite typically shows a earthy luster.
4
Match the color range
Compare against the expected color range: yellow, yellow-brown.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: fibrous, powdery, crusts.

Often confused with

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

mineral

Ilsemannite

Mohs 1-2

How to tell apart: Streak differs — Moluranite leaves yellow, Ilsemannite leaves blue-black; luster reads earthy on Moluranite and dull on Ilsemannite.

How to tell apart: Luster reads earthy on Moluranite and silky on Molybdite.

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Often found alongside moluranite

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

All properties

Chemical formula: H₄U(UO₂)₂(MoO₄)₅·18H₂O
Mohs hardness: 2
Density: 3.5 g/cm³
Colors: Yellow Yellow-brown
Streak: Yellow
Luster: Earthy
Transparency: Opaque
Crystal system: Monoclinic
Crystal habit: Fibrous, Powdery, Crusts
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Oxidized Uranium-molybdenum Deposits
Typical price: $50-300 per specimen

Where rockhounds find moluranite

Classic worldwide localities

Bayan-Mod, Mongolia
Kazakhstan

Field-hunting tip

Look in oxidized uranium-molybdenum deposits country — that is the host setting where moluranite typically forms. If you start seeing quartz, molybdenite, uraninite in float, you are in the right ground. Field specimens usually show a fibrous, powdery, crusts habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify moluranite?+

Mohs hardness is 2. It typically shows a earthy luster. The streak is yellow. Common colors include yellow, yellow-brown.

Where is moluranite found?+

Notable localities include Bayan-Mod, Mongolia; Kazakhstan.

How much is moluranite worth?+

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

Is moluranite safe to handle?+

This mineral is radioactive. Radioactive mineral; handle with care using gloves and store in a lead-lined container or away from other specimens. Do not inhale dust or ingest particles. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like moluranite?+

Moluranite is most often confused with Ilsemannite, Molybdite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with moluranite?+

Moluranite commonly co-occurs with Quartz, Molybdenite, Uraninite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does moluranite form in?+

Moluranite typically forms in oxidized uranium-molybdenum deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is moluranite used for?+

Moluranite is used in collector.

Find moluranite on the map

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