The potential sapphire display of the iPhone 6 has been rumored, substantiated and confirmed several times over the past year, but all we’ve ever heard about sapphire are its advantages. It’s durable, it’s scratch-resistant and Apple has even had experience using it in the past on protective glass covering the iPhone camera and the home button of the 5s, but there must be a downside, right? Right. Engadget’s Brad Molen spoke with several influential representatives of the smartphone industry to put together the other side of the story, and all of a sudden, sapphire isn’t looking quite like the dream material we thought it might be. “The cost and supply aren’t where we’d like them to be for sapphire to be