A cerium-oxygen compound, commonly represented as CeO2, used in many glass-polishing systems as an abrasive and chemically active polishing medium.
Cerium(IV) oxide sample — Walkerma, Wikimedia Commons, public domain · Image source · Image source
Meaning and boundaries
Cerium oxide is not one uniform commercial product and is not automatically safe for every glass, coating, slurry condition, or application.
Why it matters in glass restoration
Particle properties, concentration, pH, contamination, pad choice, pressure, speed, heat, and glass composition can change removal rate and finish quality.