I have a little dilemma. Several years ago I purchased a baking stone from a local pottery supply store. The material is cordierite-mullite. It is quite large, and has become almost impossible for me to move it in and out of the oven. I am looking for a thinner and a little smaller baking stone. Besides, I have never been quite happy with the way it often burns the bread on the bottom when baking at high temperatures. I attribute it to the material but I have never had a baking stone that is all cordierite to be able to compare. I also did not condition my stone before using it for baking. Would that explain why the breads burn? Does cordierite perform better than cordierite-mullite? I've seen great reviews of Old Stone Oven baking stone but the available size is too small. There is also cordierite available from www.northwestsourdough.com (http://www.northwestsourdough.com/store ). This one is closer to the size I am looking for. And last, there is one available from www.nybakers.com  (http://nybakers.com/index.php?main_page=product_info&cPath=8&products_id=11 ) but it's quite pricey with the added shipping cost.
I would appreciate your input. Thank you!