Phonolite

A silica-poor volcanic rock that splits into plates and rings when struck.

Phonolite specimen — Photo: No machine-readable author provided. Siim assumed (based on copyright claims)., CC BY-SA 3.0, via Wikimedia Commons

How to identify phonolite

Gray-green, fine-grained, slightly greasy.
Splits into flat slabs.
Rings like a bell when hit.

Often confused with

Trachyte
Trachyte is rougher and contains no nepheline.
Compare side by side
Basalt
Basalt is darker and heavier.
Compare side by side

Where it's found

Devils Tower, Wyoming
Mount Teide, Canary Islands
Bohemia, Czech Republic

Uses

Roofing slabs and building stone.

Rock tumbling

Can be tumbled with care.

Did you know?

Its name means 'sounding stone' — a ringing tone gave it away.

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