In the tech equivalent of a turkey dissing Thanksgiving dinners, Corning SVP Tony Tripeny has criticized sapphire as a material for protecting phone screens, coming up with a whole list of claimed drawbacks, reports CNET.

We see a lot of disadvantages of Sapphire versus Gorilla Glass. It’s about 10 times more expensive. It’s about 1.6 times heavier. It’s environmentally unfriendly. It takes about 100 times more energy to generate a Sapphire crystal than it does glass. It transmits less light which…means either dimmer devices or shorter battery life. It continues to break. I think while it’s a scratch resistant product it still breaks and our testing says that Gorilla Glass [can take] about 2.5 times more pressure that it can take.

Sapphire is far more resistant to scratches than Gorilla Glass, but Corning argue that it is more likely to be smashed.

Apple is expected to switch to a sapphire coating for the iPhone 6, manufacturing the material at the plant it jointly operates with GTAT in Arizona. While the material is indeed currently much more expensive than glass, it has been suggested that the costs could be substantially reduced with new production techniques.