Always handle with clean gloves to avoid fingerprints/oils. Clean with deionized water, isopropyl alcohol, or mild detergents; for critical applications, use 7-10% ammonium bifluoride solution (max 10 minutes) followed by thorough rinsing. Avoid sudden temperature shocks (though quartz excels at thermal shock resistance), scratches, and HF exposure unless intentional etching. Proper care extends lifespan in semiconductor and lab environments.