Amazon has a 1 day sale in progress for baking/pizza stones, likely for the (US) Memorial Day holiday. Example below, it seems to be more than 1 size/shape, and several vendors. Search Amazon for other sizes/shapes.
https://smile.amazon.com/dp/B06XGV3RS4/ref=cm_sw_r_cp_apa_glt_fabc_Z8704FNDT0SGGJVBHA8Z
I am still waiting for one of them to figure out that the perfect stone size for a standard 30" range is 18", not 16".
Looks like they do have those as well, if you're interested.