baking stone

That's a great question. Ours cracked, too (the second time we used it!), but we've been using it anyway, just making sure to push the pieces back together before baking on it. I'd be interested in other people's ideas. 

If you go to a  "kitchen store" you can usually find either small, round pizza stones or larger rectangular stones, about 1/2 or 3/4" thick.  I have two of each (summer and winter lodgings,) and I have never cracked one, even though they are often sprayed with streams of water while at 500 degrees.  The point is, that while a little more expensive, they perform.

If you live in the Southwest or in Florida, maybe in some other parts of the country, you can get a cheap Saltillo Floor tile.  They go for a buck or two.  I had a few shipped up here in the Northeast for the price of shipping, and they do work very well.  You can get 16" X 16" X 7/8" tiles.  Unfortunately, while baking pizza very nicely, the one I was using cracked into three pieces while baking a casserole at about 350 F.  Go figure.  In any event, if you can buy them locally where you live they might be a good option.

Bluestone was recently mentioned.  It is a form of siltstone/sandstone that is found here in NY - Catskill Mountains (Though, I suspect other parts of the country have similar geology to mine).  It generally has a very smooth surface even though it is just split along bedding planes.  Could be cut to fit and should be very cheap.  It is a good porosity that would allow any water to escape from it and should be good for baking on.  Shale on the other hand, which some have suggested using, is not porous, and trapped water may make it "pop" when heated.  It also tends to flake.

Good luck.  I have another idea in my back pocket that I would like to test.  Hmmmm Someday!! When there is time.

PM

www.superpeel.com

I'm still a fan of the Fibrament baking stone. I will admit I didn't try any of the other baking stone ideas that I encountered searching postings on this site but I've been nothing but happy with my purchase.

The Fibrament is thick, holds heat well, and supposedly if you follow the manufacturers instructions it shouldn't break. I routinely take mine up to 550 degrees F. and toss raw dough on top and chuck ice cubes into a cast iron skillet directly below to steam the oven.

You can find pricing information at http://www.bakingstone.com/. Mine was only $66. Not too shabby considering I shattered a $20 round pizza stone from Target after baking 3 loaves with steam.

Just my $.02

I wonder just how thick that stone was that shattered into 4 pieces. What was if made of? Was it in  use when it broke? Was it cured as the manufacturer recommended? Did it break under circumstances of rapid temperature change?

Fibrament makes a 3/4" stone up to 18X24". Seems nuff for baguettes. Any larger would not fit into my oven and leave an inch on sides and back as recommended.

Fibrament will also make a custom-sized stone:

"Custom and standard sizes are available in thicknesses to 2" and plate sizes to 32" x 48" Now that should hold a baguette.

Willard

I use unglazed quarry tiles, and am very happy with them.  I got them several years ago at Home Depot on sale for about 20 cents each.  They are the same texture and color as terra cotta flowerpots.  I chose an American brand because I was afraid of lead, but I've since heard that lead would only be in a glaze, not the tile itself.  Mine are 6"-square and almost 1/2" thick.  I use two rows of 3, making a 12x18" tile surface.  I "tempered" the new tiles by putting them in a cold oven and raising the temp every half hour until I got to 450 F., and baked them for a good hour or two.  I use them up to 500 degrees, which is the hottest my oven goes, without a problem.  Knock wood, I've never broken one, and that includes moving from Chicago to Florida to New Jersey.  Every few months when they start looking disgusting from pizza droppings, I put them through the self-cleaning cycle of the oven, and they look brand new.  I don't know how they compare to fibrament, etc., but compared to nothing, they make a huge difference.  You can try them for a few bucks.  Be sure to preheat the oven at least 45 minutes when you use them.