Gaotaiite is an extremely rare platinum-group telluride mineral discovered in the platinum-rich deposits of Gansu, China. It is typically found as microscopic grains associated with other base metal sulfides and rare minerals, requiring professional identification methods for confirmation.

Hardness

Mohs

Luster

Metallic

Streak

Black

Transparency

Opaque

mineralrare

Gaotaiite

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

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Is this gaotaiite?

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 gaotaiite with a known reference. Gaotaiite 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. Streak: black.
3
Read the luster
Hold the specimen under a strong light. Luster: metallic.
4
Match the color range
Compare against the expected color range: steel black.
5
Look at form & habit
Crystal system: cubic. Typical habit: granular.

Often confused with

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

mineral

Cooperite

Mohs 4-5

How to tell apart: Cooperite is the harder of the two (Mohs 4-5 vs. 3).

How to tell apart: Sperrylite is the harder of the two (Mohs 6-7 vs. 3).

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Often found alongside gaotaiite

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

All properties

Chemical formula: Ir₃Te₈
Mohs hardness: 3
Density: 9.97 g/cm³
Colors: Steel black
Streak: Black
Luster: Metallic
Transparency: Opaque
Crystal system: Cubic
Crystal habit: Granular
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: In crushed chromite ores and placer concentrates

Where rockhounds find gaotaiite

Classic worldwide localities

Near the village of Gaotai, about 200 km NNE of Beijing, People's Republic of China (type locality)

Field-hunting tip

Where it forms: In crushed chromite ores and placer concentrates. If you start seeing iridium, osmium, osmiridium in float, you are in the right ground. Typical habit: granular. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify gaotaiite?+

Mohs hardness is 3. Luster: metallic. The streak is black. Common colors include steel black.

Where is gaotaiite found?+

Notable localities include Near the village of Gaotai, about 200 km NNE of Beijing, People's Republic of China (type locality).

Is gaotaiite safe to handle?+

Contains tellurium and iridium; do not ingest or inhale dust. Wash hands thoroughly after handling and store securely to prevent accidental exposure.

What rocks look like gaotaiite?+

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

What minerals are found with gaotaiite?+

Gaotaiite commonly co-occurs with Iridium, Osmium, Osmiridium, Ferrian platinum, Isoferroplatinum, Iridisite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does gaotaiite form in?+

Where it forms: In crushed chromite ores and placer concentrates. Working float back to the host body is the standard way to chase a fresh occurrence.

What is gaotaiite used for?+

Gaotaiite is used in collector.

Find gaotaiite on the map

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