Metazeunerite is a copper uranyl arsenate that typically forms in the oxidized zones of uranium deposits. Collectors should look for thin, square, emerald-green tabular crystals or bright green crusts, which are often mistaken for the closely related Zeunerite.

Hardness

2-2.5

Mohs

Luster

Vitreous, pearly on {001}

Streak

Greenish white

Transparency

Transparent to translucent

mineraluncommonMeta-autunite Group family

Metazeunerite

Hardness: 2-2.5
Luster: Vitreous, pearly on {001}
Streak: Greenish white
Transparency: Transparent to translucent

Is this metazeunerite?

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 metazeunerite with a known reference. Metazeunerite 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: greenish white.
3
Read the luster
Hold the specimen under a strong light. Luster: vitreous, pearly on {001}.
4
Match the color range
Compare against the expected color range: emerald green, green, grass green.
5
Look at form & habit
Crystal system: tetragonal. Typical habit: tabular crystals, micaceous aggregates, crusts.

Often confused with

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

mineral

Zeunerite

Mohs 2.5

How to tell apart: Streak differs, so Metazeunerite leaves greenish white, Zeunerite leaves pale green.

How to tell apart: Streak differs, so Metazeunerite leaves greenish white, Torbernite leaves pale green.

Compare →

Often found alongside metazeunerite

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

All properties

Chemical formula: Cu(UO₂)₂(AsO₄)₂·8H₂O
Mohs hardness: 2-2.5
Density: 3.64 g/cm³
Colors: Emerald green Green Grass green
Streak: Greenish white
Luster: Vitreous, pearly on {001}
Transparency: Transparent to translucent
Crystal system: Tetragonal
Crystal habit: Tabular crystals, micaceous aggregates, crusts
Cleavage: Perfect on {001}; distinct on {010}
Fluorescence: Dull yellow green under SW and LW UV
Rarity: Uncommon
Uses: Collector
Host rock: An uncommon secondary mineral in the oxidized zone of arsenic-bearing hydrothermal uranium deposits

Where rockhounds find metazeunerite

Classic worldwide localities

Centennial Eureka mine, Tintic district, Juab Co., Utah, USA
Majuba Hill mine, Antelope district, Pershing Co., Nevada, USA
Grandview mine, Grand Canyon, Coconino Co., Arizona, USA
Weisser Hirsch mine, Neustädtel-Schneeberg, Saxony, Germany
Anton mine, Heubachtal, near Schiltach, Black Forest, Germany
Wheal Gorland, Gwennap, and at Wheals Owles and Edward and the Geevor mine, St. Just, Cornwall, England

Field-hunting tip

Where it forms: An uncommon secondary mineral in the oxidized zone of arsenic-bearing hydrothermal uranium deposits. If you start seeing torbernite, trögerite, walpurgite 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 metazeunerite?+

Mohs hardness is 2-2.5. Luster: vitreous, pearly on {001}. The streak is greenish white. Common colors include emerald green, green, grass green.

Where is metazeunerite found?+

Notable localities include Centennial Eureka mine, Tintic district, Juab Co., Utah, USA; Majuba Hill mine, Antelope district, Pershing Co., Nevada, USA; Grandview mine, Grand Canyon, Coconino Co., Arizona, USA; Weisser Hirsch mine, Neustädtel-Schneeberg, Saxony, Germany; Anton mine, Heubachtal, near Schiltach, Black Forest, Germany.

Is metazeunerite safe to handle?+

Metazeunerite contains arsenic, copper and uranium or thorium and calls for real care. Contains uranium and arsenic. Handle with caution, use gloves, avoid dust inhalation, and wash hands thoroughly after contact. Store in a lead-lined container or a sealed box away from living areas.

What rocks look like metazeunerite?+

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

What minerals are found with metazeunerite?+

Metazeunerite commonly co-occurs with Torbernite, Trögerite, Walpurgite, Uranospinite, Erythrite, Mimetite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does metazeunerite form in?+

Where it forms: An uncommon secondary mineral in the oxidized zone of arsenic-bearing hydrothermal uranium deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is metazeunerite used for?+

Metazeunerite is used in collector.

Find metazeunerite on the map

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