I am looking to build a "fire place" of sorts. I need to use a solid material around the heating unit/fire that can absorb heat and slowly radiate it for a long period of time. I know there are masonry heaters that does this well. They mostly use refactory bricks (fire bricks). Is there any other material that would be even better? Any particular stone, or stone composite that would be better? What about the possibility of manufacturing a stone composit with better properties than those already in ecistence?
