Analcime

A zeolite forming glassy 24-faced crystals in basalt cavities.

Analcime specimen — Photo: Ivar Leidus, CC BY-SA 4.0, via Wikimedia Commons

How to identify analcime

Clear to white trapezohedra (ball-like, 24 faces).
In cavities of basalt with other zeolites.
Hardness about 5.

Often confused with

Leucite
Leucite is embedded in lava, not in open cavities.
Compare side by side
Garnet
Garnet is colored and harder.
Compare side by side

Where it's found

Cyclopean Isles, Sicily
Mont Saint-Hilaire, Quebec
New Jersey
Nova Scotia

Uses

Collector specimens.

Rock tumbling

Not suitable for tumbling.

Did you know?

Its name means 'weak' in Greek — it picks up only a weak static charge when rubbed.

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