Metatorbernite is a dehydration product of torbernite, characterized by its vibrant emerald-green, tabular crystals. Collectors should look for distinct square, micaceous plates typically found in the weathered zones of uranium deposits.

Hardness

2.5

Mohs

Luster

Vitreous, subadamantine, pearly on {001}

Streak

Light green

Transparency

Transparent to translucent

mineraluncommonMeta-autunite Group family

Metatorbernite

Hardness: 2.5
Luster: Vitreous, subadamantine, pearly on {001}
Streak: Light green
Transparency: Transparent to translucent

Is this metatorbernite?

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 metatorbernite with a known reference. Metatorbernite sits at Mohs 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: light green.
3
Read the luster
Hold the specimen under a strong light. Luster: vitreous, subadamantine, pearly on {001}.
4
Match the color range
Compare against the expected color range: light green, dark green.
5
Look at form & habit
Crystal system: tetragonal. Typical habit: tabular crystals, micaceous aggregates, crusts.

Often confused with

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

mineral

Torbernite

Mohs 2-2.5

How to tell apart: Streak differs, so Metatorbernite leaves light green, Torbernite leaves pale green.

How to tell apart: Streak differs, so Metatorbernite leaves light green, Autunite leaves pale yellow.

How to tell apart: Streak differs, so Metatorbernite leaves light green, Meta-autunite leaves yellow; luster reads vitreous, subadamantine, pearly on {001} on Metatorbernite and pearly to dull on Meta-autunite.

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Often found alongside metatorbernite

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

All properties

Chemical formula: Cu(UO₂)₂(PO₄)₂·8H₂O
Mohs hardness: 2.5
Density: 3.52-3.70 g/cm³
Colors: Light green Dark green
Streak: Light green
Luster: Vitreous, subadamantine, pearly on {001}
Transparency: Transparent to translucent
Crystal system: Tetragonal
Crystal habit: Tabular crystals, micaceous aggregates, crusts
Cleavage: Perfect on {001}; indistinct on {010}
Rarity: Uncommon
Uses: Collector, Reference specimen
Host rock: Typically a secondary mineral, a dehydration product of torbernite formed during weathering; formed directly above 75 °C

Where rockhounds find metatorbernite

Classic worldwide localities

First described from Schneeberg, Saxony, Germany
Gunnislake mine, Calstock, Cornwall, England, is thought to be primary

Field-hunting tip

Where it forms: Typically a secondary mineral, a dehydration product of torbernite formed during weathering; formed directly above 75 °C. If you start seeing torbernite, meta-autunite in float, you are in the right ground. Typical habit: tabular crystals, micaceous aggregates, crusts. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify metatorbernite?+

Mohs hardness is 2.5. Luster: vitreous, subadamantine, pearly on {001}. The streak is light green. Common colors include light green, dark green.

Where is metatorbernite found?+

Notable localities include First described from Schneeberg, Saxony, Germany; Gunnislake mine, Calstock, Cornwall, England, is thought to be primary.

Is metatorbernite safe to handle?+

Metatorbernite contains copper and uranium or thorium and calls for real care. This mineral is radioactive and contains copper and uranium. Always wash hands after handling, avoid inhaling dust, and store in a sealed container away from living areas.

What rocks look like metatorbernite?+

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

What minerals are found with metatorbernite?+

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

What kind of rock does metatorbernite form in?+

Where it forms: Typically a secondary mineral, a dehydration product of torbernite formed during weathering; formed directly above 75 °C. Working float back to the host body is the standard way to chase a fresh occurrence.

What is metatorbernite used for?+

Metatorbernite is used in collector, reference specimen.

Find metatorbernite on the map

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