What is Erionite?
Erionite is a fibrous zeolite-group mineral occurring as delicate white to pale aggregates in altered volcanic rocks.
Mineralogy and structure
Reference formula: (K2,Na2,Ca)Al9Si27O72·27H2O. Erionite is a compositional series with Ca-, K- and Na-dominant members. Its fibrous habit is a serious handling concern: do not disturb, crush or use loose material in interiors.
Colour and appearance
Typical colours include white, colourless, pink, brown. The usual fibrous, acicular, radiating habit and vitreous, pearly lustre are useful descriptive features, but colour alone is not diagnostic.
Formation and localities
Erionite forms in or is associated with diagenetic alteration of volcanic tuffs and alkaline volcanic environments. Important documented localities include Turkey, the United States, New Zealand and other volcanic regions.
Collecting and care
Keep sealed and untouched; never cut, brush, drill or disperse fibrous erionite, and seek specialist advice for suspect material.
Erionite in popular symbolism
Modern crystal guides sometimes associate Erionite with symbolic themes based on colour or collecting tradition. These associations are cultural interpretations, not mineralogical or medical properties.
