Using a baking stone on a charcoal grill

I tried using a baking stone on a charcoal grill only to find out one does not place this item over hot coals. It only took a minute before the stone fractured. What can be done to prevent this hazard? Would I heat the stone in the oven prior to placing it over the coals?

I do similar to the attached picture. It takes a little getting use to but turns out fantastic pizza. There is a gadget that sits on top of a Weber grill for making woodfired pizzas. It comes with a peel,Stone and the oven extension.

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