Stilbite

Stilbite properties at a glance

Geology & background

Stilbite is a zeolite that crystallizes in cavities and fractures of basaltic volcanic rocks, as well as in some hydrothermal veins and metamorphic settings.

Stilbite was among the first zeolites described in early mineralogy, and its abundance in volcanic rocks made it an important reference mineral in the study of zeolite formation.

How to identify Stilbite

• Look for sheaf-like or bowtie-shaped crystal bundles with a pearly luster on cleavage surfaces.
• Low hardness near 3.5 to 4, low density, and occurrence in basalt cavities are strong clues.
• White to salmon-pink color with other zeolites such as apophyllite supports the identification.

Where Stilbite is found

Stilbite occurs in cavities of basaltic volcanic rocks, with notable specimen localities in India, Iceland, the United States, Scotland, Brazil, and Italy.

How much is Stilbite worth?

Value depends on crystal size, color, sharpness of sheaf groups, associated minerals, and locality.

Common uses

• Collector and display specimens
• Zeolite group reference mineral
• Mineralogy teaching material

Interesting facts

• The name comes from a Greek word for luster, describing its bright pearly sheen on cleavage surfaces.
• Stilbite crystals frequently group into wheat-sheaf or bowtie bundles that are instantly recognizable.
• It is a hydrated zeolite and slowly loses water when heated, a property shared across the zeolite group.
• The basalt traps of India have produced famous large salmon-colored stilbite specimens.

Care & safety

Stilbite is soft and somewhat fragile, so crystal sprays chip and abrade easily.

Avoid inhaling dust. Do not cut, grind, or polish unknown specimens without eye protection and a proper respirator.

Related rocks & minerals

Heulandite Minerals Apophyllite Minerals Calcite Minerals Quartz Quartz Family Cavansite Minerals Jadeite Silicate Minerals