Potarite is a rare palladium-mercury intermetallic compound found primarily in alluvial diamond-bearing gravels. It typically occurs as small, silvery-white metallic grains or nuggets that are notable for their unusually high density due to their mercury content.

Hardness

3.5

Mohs

Luster

Metallic, bright

Streak

Silver-white

Transparency

Opaque

mineralrare

Potarite

Hardness: 3.5
Luster: Metallic, bright
Streak: Silver-white
Transparency: Opaque

Is this potarite?

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 potarite with a known reference. Potarite sits at Mohs 3.5, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: silver-white.
3
Read the luster
Hold the specimen under a strong light. Luster: metallic, bright.
4
Match the color range
Compare against the expected color range: silver white.
5
Look at form & habit
Crystal system: tetragonal. Typical habit: nuggets.

Often confused with

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

How to tell apart: Palladium is the harder of the two (Mohs 4.5-5 vs. 3.5).

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Often found alongside potarite

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

All properties

Chemical formula: PdHg
Mohs hardness: 3.5
Density: 14.88 g/cm³
Colors: Silver white
Streak: Silver-white
Luster: Metallic, bright
Transparency: Opaque
Crystal system: Tetragonal
Crystal habit: Nuggets
Cleavage: None
Rarity: Rare
Uses: Collector, Scientific study
Host rock: In chromitite and dunite ultramafics; in placers for gold and diamonds

Where rockhounds find potarite

Classic worldwide localities

Fox Gulch, Goodnews Bay, Alaska, and in the Boss mine, Goodsprings district, Clark Co., Nevada, USA
Placers in the Kangaruma district, Potaro River area, and at Amu Creek, Essequibo River, Guyana
Morro de Pilar, and in placers in the Bom Succeso Stream, northwest of Serro, Minas Gerais, Brazil
Starchrome chromitite, Thetford Mines ophiolite, Quebec, Canada
Kytlym and Uktus complexes, Ural Montains, Russia
Brancaga massif, northern Portugal

Field-hunting tip

Where it forms: In chromitite and dunite ultramafics; in placers for gold and diamonds. If you start seeing platinum, palladium, gold in float, you are in the right ground. Typical habit: nuggets. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify potarite?+

Mohs hardness is 3.5. Luster: metallic, bright. The streak is silver-white. Common colors include silver white.

Where is potarite found?+

Notable localities include Fox Gulch, Goodnews Bay, Alaska, and in the Boss mine, Goodsprings district, Clark Co., Nevada, USA; Placers in the Kangaruma district, Potaro River area, and at Amu Creek, Essequibo River, Guyana; Morro de Pilar, and in placers in the Bom Succeso Stream, northwest of Serro, Minas Gerais, Brazil; Starchrome chromitite, Thetford Mines ophiolite, Quebec, Canada; Kytlym and Uktus complexes, Ural Montains, Russia.

Is potarite safe to handle?+

Potarite contains mercury and calls for real care. Contains mercury, which is highly toxic. Handle with care, avoid contact with skin, ingestion, or inhalation of dust, and wash hands thoroughly after handling.

What rocks look like potarite?+

Potarite is most often confused with Native Silver, Palladium. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with potarite?+

Potarite commonly co-occurs with Platinum, Palladium, Gold, Pd–Hg compounds, Pentlandite, Chalcopyrite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does potarite form in?+

Where it forms: In chromitite and dunite ultramafics; in placers for gold and diamonds. Working float back to the host body is the standard way to chase a fresh occurrence.

What is potarite used for?+

Potarite is used in collector, scientific study.

Find potarite on the map

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