Why Apple Didn’t Use Sapphire iPhone Screens
I don’t doubt that over time, there could be some breakthroughs with sapphire and new coating processes that could make it possible to use on a smartphone. However, from the research I did, it does not appear that it could happen anytime soon. Plus, sapphire’s less flexible and more brittle nature suggests, as least to me, that using it in large-screen smartphones would still be difficult — even if it was possible to coat it in a way to keep the screen from splintering. I now at least understand why Apple didn’t use it in the new iPhones — and the more I study this, it seems that it could be problematic for Apple to use sapphire outside of its smartwatch line anytime in the near future.
Update (2014-09-24): Dr. Drang:
The Mohs hardness number is a measure of scratch resistance, and it’s perfectly true that higher is better when it comes to avoiding scratches. It’s certainly a type of strength that needs to be considered, but not to the exclusion of others. If you drop your phone on a concrete sidewalk, scratch resistance isn’t going to save your screen. You need impact resistance, which involves the ability to absorb energy. For a thin sheet, that usually means the ability to flex significantly without breaking—not a property that’s intrinsically allied with scratch resistance.
Tim Bajarin at Time was promoting sapphire in August, but to his credit, he got himself educated after the iPhone 6 introduction and wrote a good explanation of why Apple stayed with Gorilla Glass. I’m not thrilled with his “sheet of ice” analogy, but the rest of the article is worth reading.
