Cesium chloride (CsCl) is a specialty inorganic salt with a mix of industrial, research, and bio-medical applications. It’s used in density-gradient ultracentrifugation (important in biotechnology labs), certain electronics and glass formulations, and less commonly in drilling fluids or specialty optical glass. Production is tied to cesium extraction from pollucite and lepidolite ores; primary producers are in regions with pollucite deposits (historically Canada, Zimbabwe, and parts of Africa and Asia), though production volumes are limited globally.