Metauramphite is a secondary uranium mineral formed through the dehydration of autunite in arid or oxidized conditions. It is typically found as small, vibrant yellow platy crystals that exhibit strong fluorescence under ultraviolet light.

Hardness

2-2.5

Mohs

Luster

Pearly

Streak

Yellow

Transparency

Translucent

mineralrareAutunite Group family

Metauramphite

Hardness: 2-2.5
Luster: Pearly
Streak: Yellow
Transparency: Translucent

No image

Is this metauramphite?

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 metauramphite with a known reference. Metauramphite sits at Mohs 2-2.5, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: yellow.
3
Read the luster
Hold the specimen under a strong light. Luster: pearly.
4
Match the color range
Compare against the expected color range: yellow, greenish-yellow.
5
Look at form & habit
Crystal system: tetragonal. Typical habit: platy crystals, micaceous aggregates.

Often confused with

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

mineral

Autunite

Mohs 2-2.5

How to tell apart: Streak differs, so Metauramphite leaves yellow, Autunite leaves pale yellow; luster reads pearly on Metauramphite and vitreous, pearly on {001} on Autunite.

How to tell apart: Streak differs, so Metauramphite leaves yellow, Torbernite leaves pale green; luster reads pearly on Metauramphite and vitreous, subadamantine, waxy, pearly on cleavages; becoming dull on dehydration to metatorbernite on Torbernite.

Often found alongside metauramphite

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

All properties

Chemical formula: (NH₄)₂(UO₂)₂(PO₄)₂·6H₂O
Mohs hardness: 2-2.5
Density: 3.5-3.6 g/cm³
Colors: Yellow Greenish-yellow
Streak: Yellow
Luster: Pearly
Transparency: Translucent
Crystal system: Tetragonal
Crystal habit: Platy crystals, micaceous aggregates
Cleavage: Perfect basal
Fluorescence: Bright yellow-green under UV
Rarity: Rare
Uses: Collector
Host rock: oxidized zones of uranium-bearing hydrothermal veins

Where rockhounds find metauramphite

Classic worldwide localities

France
Czech Republic
Germany
USA
Kazakhstan

Field-hunting tip

Where it forms: oxidized zones of uranium-bearing hydrothermal veins. If you start seeing uraninite, gummite, autunite in float, you are in the right ground. Typical habit: platy crystals, micaceous aggregates. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify metauramphite?+

Mohs hardness is 2-2.5. Luster: pearly. The streak is yellow. Common colors include yellow, greenish-yellow.

Where is metauramphite found?+

Notable localities include France; Czech Republic; Germany; USA; Kazakhstan.

Is metauramphite safe to handle?+

Metauramphite contains uranium or thorium and calls for real care. This mineral contains uranium and is highly radioactive. It should be stored in a lead-lined container, handled with gloves, and kept away from living areas to avoid inhaling radioactive dust.

What rocks look like metauramphite?+

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

What minerals are found with metauramphite?+

Metauramphite commonly co-occurs with Uraninite, Gummite, Autunite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does metauramphite form in?+

Where it forms: oxidized zones of uranium-bearing hydrothermal veins. Working float back to the host body is the standard way to chase a fresh occurrence.

What is metauramphite used for?+

Metauramphite is used in collector.

Find metauramphite on the map

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