TiC Is really a form of incredibly difficult ceramic, and it may even be extra scratch-resistant than sapphire using a Mohs hardness rating up to nine.5. The bezel is usually topped with sapphire, supplying as much defense as possible into the micro fuel tubes that variety the markers. 1844: Adolphe https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/