Pollucite, a Rare Fluorescent Cesium-Containing Zeolite Mineral
Contributed by: Chris Clemens
minID: 0MT-AUW
Date: Apr 16th, 2026
Locality: Valor Lithium Occurrence, La Corne, Abitibi RCM, Abitibi-Témiscamingue, Québec, Canada (See on Mindat)
Size: 5.6 x 2.5 x 9.4 cm
Weight: 102 g
Description:
Here is one for the connoisseur of rare fluorescent mineral species. Pollucite, a cesium-containing zeolite, is not particularly rare, but the fluorescence in pollucite is quite uncommon. This specimen shows pale yellow fluorescence under shortwave and midwave UV and was collected in 2019 by Mark Jacobson, current president of the Friends of Mineralogy, from the Valor Lithium and Cesium Pegmatite occurrence in Quebec, Canada. Interestingly, little to no fluorescence is produced under longwave UV.
Pollucite is mined as a commercial source for the element cesium. This pollucite specimen has a white to purple-pink color under white light, and it is composed of small intergrown crystal plates.
Originally posted by Chris Clemens on Nature's Rainbows in 2023.
Summary of luminescence responses:
Pollucite (Mindat) (RRUFF)
- Fluorescence under Shortwave (254nm Lamp/Mercury) UV light: Yellow
- Fluorescence under Midwave (305nm Lamp/Mercury) UV light: Yellow