Mopungite is a rare secondary mineral typically occurring in the oxidized zones of antimony deposits. It is best identified by its colorless to white tetragonal bipyramidal crystals, usually found associated with other antimony oxidation products like stibiconite.

Hardness

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrare

Mopungite

Hardness: 3
Luster: Vitreous
Streak: White
Transparency: Transparent

Is this mopungite?

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 mopungite with a known reference. Mopungite 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. Mopungite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Mopungite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: white, colorless.
5
Look at form & habit
Crystal system: tetragonal. Typical habit: bipyramidal crystals.

Often confused with

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

mineral

Stibiconite

Mohs 5-5.5

How to tell apart: Stibiconite is the harder of the two (Mohs 5-5.5 vs. 3); luster reads vitreous on Mopungite and dull on Stibiconite.

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Often found alongside mopungite

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

All properties

Chemical formula: NaSb(OH)₆
Mohs hardness: 3
Density: 5.71 g/cm³
Colors: White Colorless
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Tetragonal
Crystal habit: Bipyramidal Crystals
Cleavage: Distinct On {111}
Rarity: Rare
Uses: Collector
Host rock: Oxidized Zones of Antimony-bearing Hydrothermal Deposits
Typical price: $50-300 per thumbnail specimen

Where rockhounds find mopungite

Classic worldwide localities

Mopung Hills, Nevada, USA
Great Basin region, USA

Field-hunting tip

Look in oxidized zones of antimony-bearing hydrothermal deposits country — that is the host setting where mopungite typically forms. If you start seeing stibnite, cervantite, stibiconite in float, you are in the right ground. Field specimens usually show a bipyramidal crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify mopungite?+

Mohs hardness is 3. It typically shows a vitreous luster. The streak is white. Common colors include white, colorless.

Where is mopungite found?+

Notable localities include Mopung Hills, Nevada, USA; Great Basin region, USA.

How much is mopungite worth?+

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

Is mopungite safe to handle?+

It contains toxic constituents. Contains antimony, which is toxic if ingested or inhaled as dust. Wash hands thoroughly after handling and avoid creating dust when breaking or cleaning specimens. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like mopungite?+

Mopungite is most often confused with Stibiconite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with mopungite?+

Mopungite commonly co-occurs with Stibnite, Cervantite, Stibiconite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does mopungite form in?+

Mopungite typically forms in oxidized zones of antimony-bearing hydrothermal deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is mopungite used for?+

Mopungite is used in collector.

Find mopungite on the map

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