What type of rock can reach a high temprature without cracking or breaking?

I'm doing a project for science where we have to design something from our ae and convert it to something that could be made in the stone age. I'm making a type of oven

The fire will be lit by a switch that cause a flint and stone to make a spark in the oven.

We need to list what types of rocks we use and the only one i haven't got is a rock that could withstand the temprature of an oven. ((It doesn't need to be super hot just say hot enough to cook a bit of meat.