Linked from
The 16 pages that link to Quartz clock, each with the reason it gives.
QuartzBroader topic: Its timing circuit exploits quartz’s piezoelectric resonance.
OscillationRelated: Crystal oscillations provide a regular timing reference.
ClockBroader topic: Quartz vibration sets the pace for common modern electronic clocks.
StopwatchRelated: Quartz technology made compact electronic stopwatches inexpensive and precise.
Alarm clockRelated: Many electronic alarm clocks use quartz oscillations to keep time accurately.