Mechanism - Quartz. The energy drawn from the battery is transferred to quartz, causing its vibration, based on which the digital system measures the current time.
Glass - Sapphire. Extremely scratch-resistant, thanks to the use of corundum - a mineral from which synthetic sapphire is made. It has 9/10 points on the Mohs scale and is the second, after diamond, the hardest material in the world.