The stone cracked due to a temp difference caused by one of these things:
1. You were supposed to heat up the water when you preheated the stone and the oven. That would give the stone time to absorb water as it heated inside the oven. I put boiling water in a cold oven to make my dough rise, then leave it there for the baking process later.
2. You did preheat the stone inside the oven at the same time, right??
3. Was you bread dough cold for any reason? Did you put corn meal on it to prevent sticking? Cornmeal is also another layer to protect the stone.
The good news is that you can get stone equivalents pretty inexpensively. Go to the local Big Box home supply store and pick up the largest terra cotta tiles you can find. Make sure that they're made in Italy and not glazed in any way. These are waaaay cheaper than the $40+ stones you can buy from kitchen stores.
1. You were supposed to heat up the water when you preheated the stone and the oven. That would give the stone time to absorb water as it heated inside the oven. I put boiling water in a cold oven to make my dough rise, then leave it there for the baking process later.
2. You did preheat the stone inside the oven at the same time, right??
3. Was you bread dough cold for any reason? Did you put corn meal on it to prevent sticking? Cornmeal is also another layer to protect the stone.
The good news is that you can get stone equivalents pretty inexpensively. Go to the local Big Box home supply store and pick up the largest terra cotta tiles you can find. Make sure that they're made in Italy and not glazed in any way. These are waaaay cheaper than the $40+ stones you can buy from kitchen stores.