Well...that makes two of us because I don't have a clue as to what a 'cooking stone' is.
ROFL!
I'll do my best to explain what the cooking stone is.
They're the size of a large pizza and round as well, made out of material kind of like terra cotta planters only much better material. When you cook a frozen or a homemade pizza on them, they help the crust on the underside get crispy. There are also recipes for cookies and other items you can use the stone for.
Unfortunately, I ordered one around 4-5 years ago and while I was "pre-seasoning" it, it broke. Since I have a difficult time getting to the post office I didn't bother to return it to the manufacturer for a replacement.
Mine probably had developed a hairline crack during the shipping process or somewhere else along the line because I've never heard anyone else have the type of problem I had. Everyone else I've ever heard say anything about Pampered Chef has raved about how much they love their cookware. (They have casserole type dishes as well as other types, all of which everyone says they do a better job than anything esle they've ever used.)
Hope I was able to shed a little light.