The $QUARTZ token is Sandclock's token. For the sake of completeness this page will list current and future utility.
Sandclock's metavaults charge a performance fee over the yield generated. The fee is owned by $QUARTZ holders. However, instead of using it for immediate value accrual, this capital is redeposited to the protocol as a SPONSOR and thus, the yield generated by this capital is used to boost all deposits, thereby creating a positive feedback loop, attracting more capital, and therefore, more fees.
In the future, if the DAO desires, a rageQuit() function can be implemented, where burning $QUARTZ will withdraw a proportional amount of the treasury to the account owner. Other value accrual mechanisms will also be considered, pending a DAO vote.
Lindy Labs is setting up a captive insurance fund. However, as all things TradFi, this is a laborious process and the ETA is hard to estimate. Staking QUARTZ and proving your uniqueness will allow you to tap into this insurance.