Hello user mlwillis,

Unfortunately we do not have the information regarding the porcelain tile material. We mainly focus on counter tops that are made from large slabs of stone.
Tile work in this project was done by Seattle Home Remodeling ( Viktor Bogun )
you can contact them threw there web site at: http://www.seattlehomeremodel.net/
Also we know that this tile came from Dal-Tile in Seattle. You could also try them if you are still having a hard time finding out the name of the material.
Please let us know if there is anything else we can help you with
-Progranite