What is Stilbite?
Stilbite is a soft zeolite-group mineral known for pearly peach, pink and white blades arranged in elegant fan and bow-tie aggregates.
Mineralogy and crystal structure
Reference formula: NaCa4Al9Si27O72·28H2O. Stilbite is a zeolite series with sodium- and calcium-dominant members. The selected COD model is a labelled representative Stilbite-Na structure, because composition and hydration vary through the series. Stilbite is classified with silicates and has a monoclinic crystal system. Typical hardness is 3.5–4 on the Mohs scale and specific gravity is approximately 2.1–2.2.
Colour, lustre and habit
Typical colours include white, cream, pink, peach, orange, yellow. The usual bladed, bow-tie, radiating habit and pearly, vitreous lustre help describe a specimen, but colour alone is not diagnostic.
Formation and notable localities
Stilbite forms in or is associated with basalt cavities, volcanic vesicles and low-temperature hydrothermal environments. Important documented localities include India, Iceland, Scotland, Canada, Australia and the United States.
The soft fan-shaped classic of zeolite collections
Stilbite sells because its crystal architecture is decorative without being artificial: peach blades and radiating fans make a strong display piece while recording fluid circulation through volcanic rock.
Collecting and care
Keep dry and protect delicate blades from impact. Avoid acids, ultrasonic cleaning and prolonged soaking.
