Sharpening Ceramic Parts

Not sure on what specific "parts" you're referring too. But how we in the culinary industry for our knives would do it is that you had to use stones and "steels" with diamond in them with different grit to get the desired sharpness. To my knowledge diamond is the only thing that can cut ceramic. Though first the ceramic must be hardened by a tempering process using high heat to harden the piece otherwise it will be brittle and easily shatter. This is just one side of it, there could be other ways and processes I'm unaware of, but this is from my experience.