Mesolite

Each needle on this mesolite specimen is a single crystal. The crystal grew from a water solution that circulated through cooled volcanic rock. They fanned out to fill a cavity left by a gas bubble in the rock. The chemical composition of mesolite is Na2Ca2(Al6Si9)O30.8H2O.

Mesolite (with Apophyllite)

Each needle in this spray of mesolite is a single crystal. The crystals grew from a water solution that circulated through cooled volcanic rock. They fanned out to fill a cavity left by a gas bubble in the rock.