I have seen a conveyor pizza oven that uses granite slabs 36 inches across and about 6 inches wide. The chain had large enough gears on the end to allow the slabs to pivot over the ends and return in a continuous belt through the oven. Thus a stone conveyor pizza oven. So, would granite make an acceptable deck stone in a gas oven? Size would be 24 x 34.5 x 1.5 inches thick.