Report Human Ash Glaze Cone 6 in Clay and Glaze Chemistry Posted August 12, 2010 Recenly my father died and I was asked to make the urn for his ashes and use part of the ashes in the glaze. I understand that most of what is left from cremation is bone ash and pulverized bone. Does anyone have any experience with this subject? I'm sorry for your loss. I know it has been done with pets, but I do not know the formulas used.