Inaglyite is a rare lead copper telluride mineral found primarily in epithermal gold-telluride deposits. It typically occurs as small, metallic inclusions within larger ore minerals and is prized by advanced micromount collectors due to its scarcity.

Hardness

2.5-3

Mohs

Luster

Metallic

Streak

Black

Transparency

Opaque

mineralrareTiemannite-group family

Inaglyite

Hardness: 2.5-3
Luster: Metallic
Streak: Black
Transparency: Opaque

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Is this inaglyite?

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 inaglyite with a known reference. Inaglyite sits at Mohs 2.5-3, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Inaglyite leaves a black streak.
3
Read the luster
Hold the specimen under a strong light. Inaglyite typically shows a metallic luster.
4
Match the color range
Compare against the expected color range: lead-gray, steel-gray.
5
Look at form & habit
Crystal system: hexagonal. Typical habit: anhedral to subhedral grains.

Often confused with

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

mineral

Galena

Mohs 2.5

How to tell apart: Streak differs, so Inaglyite leaves black, Galena leaves lead-gray.

How to tell apart: Streak differs, so Inaglyite leaves black, Tetradymite leaves lead-gray.

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Often found alongside inaglyite

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

All properties

Chemical formula: PbCu₃Ir₈S₁₆
Mohs hardness: 2.5-3
Density: 8.8-9.2 g/cm³
Colors: Lead-gray Steel-gray
Streak: Black
Luster: Metallic
Transparency: Opaque
Crystal system: Hexagonal
Crystal habit: Anhedral to Subhedral Grains
Cleavage: In Two Directions
Rarity: Rare
Uses: Collector
Host rock: Epithermal Gold Deposits

Where rockhounds find inaglyite

Classic worldwide localities

Inagli massif, Yakutia, Russia

Field-hunting tip

Look in epithermal gold deposits country, the host setting where inaglyite typically forms. If you start seeing altaite, gold, pyrite in float, you are in the right ground. Field specimens usually show a anhedral to subhedral grains habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify inaglyite?+

Mohs hardness is 2.5-3. It typically shows a metallic luster. The streak is black. Common colors include lead-gray, steel-gray.

Where is inaglyite found?+

Notable localities include Inagli massif, Yakutia, Russia.

Is inaglyite safe to handle?+

It contains toxic constituents. Contains copper and lead, which are toxic if ingested or inhaled as dust. Wash hands thoroughly after handling and avoid creating dust. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like inaglyite?+

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

What minerals are found with inaglyite?+

Inaglyite commonly co-occurs with Altaite, Gold, Pyrite, Chalcopyrite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does inaglyite form in?+

Inaglyite typically forms in epithermal gold deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is inaglyite used for?+

Inaglyite is used in collector.

Find inaglyite on the map

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