Burnt Pizza Stone

My daughter got me a pizza stone over the weekend and I just used it for the first time. After Tony and I had got our pizza and left the kitchen my husband, not realizing that the burner under the tea kettle on the back burner was on, accidentally slid the pizza stone back and partially onto that burner. After he came on in the livingroom I kept smelling something. Thinking that it was the pan that he had made some extra sauce in, I didn't pay too much attention (I'm used to him cooking his sauce on a higher temperature than I use and sometimes he scorches it a little). Pretty soon my eyes were burning. I went in the kitchen to discover the edge of the pizza stone was over the burner that the tea kettle was on (the tea kettle was on to put some humidity in the house due to my plugged sinuses). Anyway, the pizza that was on the stone directly over the burner was burned and blackened almost all the way through and the stone itself has a big black mark on it. I've tried cleaning it with baking soda and water and I've tried removing it with sandpaper. The mark isn't as dark as it was, but it's still black. I don't really think it will hurt it. It just looks bad. But if anyone has any advice on what I can try next, please, contact me. Thank you so much!

~Rebecca