What is the name of Rolex's patented ceramic bezel technology?

Rolex’s patented ceramic bezel technology is called Cerachrom.

Rolex developed Cerachrom for its Professional watch models, introducing the first ceramic bezel insert on the GMT-Master II in 2005. The name combines “ceramic” with “chrom,” derived from the Greek word for colour. It identifies Rolex’s proprietary high-technology ceramic components rather than ceramic material in general.

Cerachrom was designed to solve weaknesses associated with older anodized-aluminium inserts. The ceramic is exceptionally hard, resistant to corrosion and virtually impervious to scratches, while its colour is not significantly affected by ultraviolet radiation. Rolex moulds the graduations into the ceramic and coats them with gold or platinum using physical vapour deposition.

A common mix-up is Chromalight, which refers to Rolex’s blue-emitting luminescent display material, not the bezel. “Ceramic” describes the material broadly; Cerachrom is Rolex’s specific branded technology. Rolex later developed two-colour monobloc Cerachrom inserts and fully ceramic bezels, including the black Daytona bezel launched in 2011.