QUESTION

How to determine if a tile is Porcelain? - Have a Victorian home that is to far gone to be restored and will begin dismantling soon. However, it has a tile fireplace. Would like to know what kind of tile it is. I thought it was marble tile. However, one corner tile broke off and revealed that it is either ceramic or porcelain. I don't know how to tell what it is. Suggestions?

ANSWER

ANSWER - The general rule of thumb for whether a ceramic tile is a porcelain type of ceramic tile or another ceramic tile body type is that the porcelain tile body cannot have an absorption rate greater than 1/2 of 1% (0.5%).   If the tile body readily absorbs water then it certainly isn't porcelain.  If it doesn't absorb readily then maybe it is porcelain or maybe it is a vitreous body (greater than .5% by not more than 3% absorption).   The only certain way to determine if it is porcelain is to test it in a laboratory.  There is a TCNA Laboratory test called the Certified Porcelain Tile Test that currently performs the ASTM C373 absorption test for $275.  Good Luck.