The remedy is to reinstall over the existing os, then the quartz comes back.
I see the quartz disappeared under 2 conditions so far,
1. os crash, reboot, no more quartz
2. when the space filling up, apps start to freeze, I close all the apps, then restart, then quartz has gone
Mine is mac air, so the space is pretty thin, pry why it happens to me so many times.
I think it has to do with the corruption of some config files, Apple should find the way to bombproof them.