Leucite

A potassium silicate forming white, ball-like 24-faced crystals in some lavas.

Leucite specimen — Photo: Dave Dyet http://www.shutterstone.com http://www.dyet.com, Public domain, via Wikimedia Commons

How to identify leucite

Dull white rounded crystals with many faces, set in lava.
Hardness about 6.
Light in weight.

Often confused with

Analcime
Analcime looks almost identical but grows in cavities, not embedded in lava.
Compare side by side
Garnet
Garnet is colored, heavier and harder.
Compare side by side

Where it's found

Mount Vesuvius, Italy
Alban Hills, Italy
Eifel, Germany

Uses

Collector specimens; historically a potash fertilizer source.

Rock tumbling

Not suitable for tumbling.

Did you know?

Its name comes from Greek leukos, 'white'.

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

Play today's Rocksday