how a quartz gets damaged
The damage usually occurs when a person pulls back the battery-arm which secures the battery, and scrapes the coil with the tweezers causing a tiny break.
Or in the more extreme case, the person pulls back the battery-arm and presses it down on the coil with the tweezer point, in order to hold it in place. If they slip off, or apply too much pressure, this can scrape / break the coil.
All it takes is 1 tiny wire…
