Objects with gold luster should be treated like fine china. Care must be taken to avoid hard scrubbing when washing your piece due to the possibility of scraping off the thin layer of precious metal. Overglazed pieces can be put into the dishwasher, but repeated washings can eventually wear the luster away. Do not Microwave objects with gold luster, unless you want to watch a fireworks show, and worst case scenario... damage your microwave.