Widenmannite is an extremely rare lead-zinc uranyl vanadate mineral that typically forms as small, tabular yellow crystals. It is primarily found in uranium-bearing hydrothermal deposits where it serves as a highly sought-after specimen for advanced mineral collectors due to its complex chemical structure.

Hardness

Mohs

Luster

Vitreous

Streak

Yellow

Transparency

Translucent

mineralrare

Widenmannite

Hardness: 3
Luster: Vitreous
Streak: Yellow
Transparency: Translucent

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Is this widenmannite?

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 widenmannite with a known reference. Widenmannite 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. Widenmannite leaves a yellow streak.
3
Read the luster
Hold the specimen under a strong light. Widenmannite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: yellow, yellowish-orange.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: tabular crystals, aggregates.

Often confused with

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

How to tell apart: Streak differs — Widenmannite leaves yellow, Autunite leaves pale yellow; luster reads vitreous on Widenmannite and pearly on Autunite.

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Often found alongside widenmannite

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

Baryte
mineral · Mohs 3-3.5

All properties

Chemical formula: Pb₂Zn(UO₂)₂(VO₄)₂(OH)₄
Mohs hardness: 3
Density: 5.68 g/cm³
Colors: Yellow Yellowish-orange
Streak: Yellow
Luster: Vitreous
Transparency: Translucent
Crystal system: Orthorhombic
Crystal habit: Tabular Crystals, Aggregates
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Hydrothermal Uranium-bearing Veins
Typical price: $50-300 per specimen

Where rockhounds find widenmannite

Classic worldwide localities

Schwarzwald, Germany
Lodève, France

Field-hunting tip

Look in hydrothermal uranium-bearing veins country — that is the host setting where widenmannite typically forms. If you start seeing uranyl-vanadate minerals, baryte in float, you are in the right ground. Field specimens usually show a tabular crystals, aggregates habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify widenmannite?+

Mohs hardness is 3. It typically shows a vitreous luster. The streak is yellow. Common colors include yellow, yellowish-orange.

Where is widenmannite found?+

Notable localities include Schwarzwald, Germany; Lodève, France.

How much is widenmannite 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 widenmannite safe to handle?+

This mineral is radioactive. It contains toxic constituents. Contains uranium and lead. Radioactive; handle with gloves, wash hands thoroughly after contact, and store in a lead-lined container or away from living areas. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like widenmannite?+

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

What minerals are found with widenmannite?+

Widenmannite commonly co-occurs with Uranyl-vanadate minerals, Baryte. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does widenmannite form in?+

Widenmannite typically forms in hydrothermal uranium-bearing veins. Working float back to the host body is the standard way to chase a fresh occurrence.

What is widenmannite used for?+

Widenmannite is used in collector.

Find widenmannite on the map

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