Formula: (Cs,Na)₂(Al₂Si₄O₁₂) · 2H₂O

Species:

Colour: Almost always colorless or white, also light gray, light pink, light blue, pale violet

Lustre: Vitreous, Sub-Vitreous, Resinous, Waxy, Greasy

Hardness: 6½

Specific Gravity: 2.9

Crystal System: Isometric

Member of: Zeolite Group

Name: Named after Pollux, a figure from Greek mythology, brother of Castor, for its common association with “castorite” (petalite). The name was later changed to the current pollucite.

Type Locality: La Speranza (Pisani’s Quarry), San Piero in Campo, Campo nell’Elba, Livorno Province, Tuscany – Italy

Isostructural with: Analcime Zeolite Group. Analcime-Pollucite Series.The cesium analogue of analcime. Related to kirchhoffite.