Icosahedrite is a remarkable natural quasicrystal found within the Khatyrka meteorite. It is noted for its forbidden rotational symmetry that does not conform to standard crystallographic patterns found in typical terrestrial minerals.

Hardness

Mohs

Luster

Metallic

Streak

Gray

Transparency

Opaque

mineralrare

Icosahedrite

Hardness: 6
Luster: Metallic
Streak: Gray
Transparency: Opaque

No image

Is this icosahedrite?

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 icosahedrite with a known reference. Icosahedrite sits at Mohs 6, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: 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: dark gray-black.
5
Look at form & habit
Crystal system: icosahedral. Typical habit: grains.

Often found alongside icosahedrite

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

All properties

Chemical formula: Al₆₃Cu₂₄Fe₁₃
Mohs hardness: 6
Density: 6.8 g/cm³
Colors: Dark gray-black
Streak: Gray
Luster: Metallic
Transparency: Opaque
Crystal system: Icosahedral
Crystal habit: Grains
Cleavage: None
Rarity: Rare
Uses: Collector, Scientific research
Host rock: Likely formed by impact-induced shock in the Khatyrka meteorite, a CV3 carbonaceous chondrite

Where rockhounds find icosahedrite

Classic worldwide localities

Khatyrka meteorite, Russia

Field-hunting tip

Where it forms: Likely formed by impact-induced shock in the Khatyrka meteorite, a CV3 carbonaceous chondrite. If you start seeing spinel, diopside, forsterite 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 icosahedrite?+

Mohs hardness is 6. Luster: metallic. The streak is gray. Common colors include dark gray-black.

Where is icosahedrite found?+

Notable localities include Khatyrka meteorite, Russia.

Is icosahedrite safe to handle?+

Icosahedrite contains copper. Wash your hands afterwards, never grind or breathe the dust, and store it apart from specimens you handle often.

What minerals are found with icosahedrite?+

Icosahedrite commonly co-occurs with Spinel, Diopside, Forsterite, Nepheline, Sodalite, Corundum. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does icosahedrite form in?+

Where it forms: Likely formed by impact-induced shock in the Khatyrka meteorite, a CV3 carbonaceous chondrite. Working float back to the host body is the standard way to chase a fresh occurrence.

What is icosahedrite used for?+

Icosahedrite is used in collector, scientific research.

Find icosahedrite on the map

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