Watches with sapphire glass

Sapphire

— glass based on technical sapphire, an artificially grown crystal of transparent corundum.

This material is characterized by extremely high hardness, due to which it can only be scratched with a special tool (for example, diamond). Thanks to this, sapphire crystals retain their "presentation" for a very long time, they do not lose transparency for decades. On the other hand, such a coating costs much more than mineral glass, not to mention plastic; and the sensitivity to impacts, especially point impacts, is rather low for sapphire (although there are also shock-proof watch models with similar glasses).