Canterra is volcanic ash and other debris that is blown out of a volcano. After time, the deposit is pressed and it solidifies into a soft rock deposit. Canterra is extremely porous and subject to staining. Canterra is so soft it is commonly carved into fireplaces, columns, statues as well as a floor tile. Canterra as a floor tile is usually a very rough cut rustic tile. Not recommended for floors unless the specifics of Canterra are considered before installation. One to consider is the grout color and grout installation. Canterra is so extremely porous that the grout can stain the stone or solidify on the stone which requires extensive cleaning after the grout has dried.