I am so happy to review these tiles.  This was the easiest project I have ever undertaken.  First of all, they look completely awesome.  I wanted a back splash behind my stove/oven and was considering glass tiles, but realizing the installation would be challenging since I have never attempted such an endeavor.  When I saw these tile squares on Wayfair, I was so impressed with the color scheme as it matched my wallpaper in my kitchen exactly.  I placed my order and they arrived in record time and in perfect condition.  They are some sort of synthetic (maybe vinyl??) and I had them in place in about 15 minutes.  They look exactly like glass tiles and I just could not be more pleased!!  I would highly recommend this product -- you will not regret it.