This is a solid piece of clay, sold raw. However a layer of sealer is recommended before installation. It measures 11 1/4"" by 11 1/4"" and it is 3/4"" thick. Using a 1/2"" grout an average of 1 sq foot will be covered with this piece. For a more accurate quantity, given a surface, give us a call to find out. The super Saltillo is a finer product than the regular one. Its edges are smooth.