Ive been wondering about granite myself, as i do work fabbing and installing granite countertops etc, ive got several scraps that would be able to be cut to fit an oven easy enough. some do come presealed on the shiny side, but most, the shine is just from being polished with superfine diamond polishing pads.
so as long as i know there are no chemical sealers, is the main issue still a chemical release from the stone? or just danger of the stone breaking during cooking?
i do have a, now broken, pizza stone that i cook on, but would like to be able to use the granite i have if its not harmful or dangerous. yes i know it is not ideal, but is it really bad?