Anyuiite is an extremely rare gold-lead intermetallic compound found primarily in placer deposits. It typically occurs as microscopic grains and is characterized by its very high density and metallic luster.

Hardness

3.5

Mohs

Luster

Metallic

Streak

Lead gray

Transparency

Opaque

mineralrare

Anyuiite

Hardness: 3.5
Luster: Metallic
Streak: Lead gray
Transparency: Opaque

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Is this anyuiite?

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 anyuiite with a known reference. Anyuiite 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: lead gray.
3
Read the luster
Hold the specimen under a strong light. Luster: metallic.
4
Match the color range
Compare against the expected color range: lead gray, silver gray.
5
Look at form & habit
Crystal system: tetragonal. Typical habit: grains.

Often confused with

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

mineral

Gold

Mohs 2.5-3

How to tell apart: Streak differs, so Anyuiite leaves lead gray, Gold leaves yellow.

How to tell apart: Streak differs, so Anyuiite leaves lead gray, Altaite leaves black.

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Often found alongside anyuiite

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

All properties

Chemical formula: AuPb₂
Mohs hardness: 3.5
Density: 13.49 g/cm³
Colors: Lead gray Silver gray
Streak: Lead gray
Luster: Metallic
Transparency: Opaque
Crystal system: Tetragonal
Crystal habit: Grains
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: In placer concentrates derived from small ultramafic-gabbroid masses in a dunite-harzburgite formation (Bol’shoi Anyui River basin, Russia); in gold concentrates from placers (Hunchun River, China)

Where rockhounds find anyuiite

Classic worldwide localities

Tributaries of the Bol’shoi Anyui River, Chukot Peninsula, far northeastern Siberia, Russia (type locality)
Sandogou placers, along the Hunchun River, Jilin Province, China

Field-hunting tip

Where it forms: In placer concentrates derived from small ultramafic-gabbroid masses in a dunite-harzburgite formation (Bol’shoi Anyui River basin, Russia); in gold concentrates from placers (Hunchun River, China). If you start seeing lead, gold, ilmenite in float, you are in the right ground. Typical habit: grains. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify anyuiite?+

Mohs hardness is 3.5. Luster: metallic. The streak is lead gray. Common colors include lead gray, silver gray.

Where is anyuiite found?+

Notable localities include Tributaries of the Bol’shoi Anyui River, Chukot Peninsula, far northeastern Siberia, Russia (type locality); Sandogou placers, along the Hunchun River, Jilin Province, China.

Is anyuiite safe to handle?+

Anyuiite contains lead. Contains lead, which is a toxic heavy metal. Wash hands thoroughly after handling and do not inhale dust.

What rocks look like anyuiite?+

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

What minerals are found with anyuiite?+

Anyuiite commonly co-occurs with Lead, Gold, Ilmenite, Titanian magnetite, Chrome spinel, Hematite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does anyuiite form in?+

Where it forms: In placer concentrates derived from small ultramafic-gabbroid masses in a dunite-harzburgite formation (Bol’shoi Anyui River basin, Russia); in gold concentrates from placers (Hunchun River, China). Working float back to the host body is the standard way to chase a fresh occurrence.

What is anyuiite used for?+

Anyuiite is used in collector.

Find anyuiite on the map

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