The Ciabatta bread recipe said spritz the top of the loaf with water when depositing it in the oven, then again within the next five minutes. So I did. What it didn't say is the your pizza/baking stone won't like the introduction of water. Maybe my spritzer seeting was too dense. All I know is my beautiful stone is now in two pieces.
I'm a novice. I don't have any advice to offer; except, if you spritz that loaf in the oven, be very careful to avoid getting ANY water on the stone. A $40 bread making lesson. I'll still use the pieces to maintain a more even oven temperature and if I keep the loaves small I can still use the pieces to support the bread through the baking cycle. Just broke my heart to hear that "snap" and see the light from the oven's interior shining through that crack.
Only redeeming factor is that the bread was fabulous.