Hi. I've been baking bread for about a year. The breads usually turn out ok. But what I'd like to do now is try using a baking stone.

My question is: what material to use? I've gone to home depots and stone shops but, as I expected, no one knew anything technical about the stones they were selling-couldn't suggest what material could be possible. I asked for unglazed quarry tiles, and got blank stares.

This is a list of the materials I encountered in those shops: ceramic tiles, marble, granite, slate, sandstone, limestone, and something called 'piedra'.

I've been reading some of the posts on this thread, and some people suggest turning up the heat gradually, over a period of an hour or so...is this true for all stones? Can I not set it right away to the 500F level in some of the 'Bread Baker's Apprentice'formulas?

Many thanks for your indulgence in an ignoramus' questions. :)