Diamond

Pure carbon crystallized deep in the mantle and carried up in kimberlite eruptions. The hardest natural material.

Diamond specimen — Photo: DGPC/ADF Luísa Oliveira, CC0, via Wikimedia Commons

How to identify diamond

Scratches everything — including corundum.
Greasy-looking, extremely bright luster even in rough crystals.
Often octahedral with slightly curved faces.
Water beads up on its surface.

Often confused with

Quartz
Quartz is far softer and has a glassy, not adamantine, luster.
Compare side by side
Topaz
Topaz is softer and cleaves along one direction.
Compare side by side

Where it's found

Jwaneng, Botswana
Yakutia, Russia
Northwest Territories, Canada
Crater of Diamonds, Arkansas

Uses

Gems, and cutting, drilling and polishing tools.

Rock tumbling

Not suitable for tumbling. Nothing to gain — and if you find one, keep it safe.

Did you know?

Your pencil's graphite is also pure carbon — same element, different crystal structure.

Think you could spot it from a blurry close-up?

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