According to “exclusive, reliable inside information” supplied to Venture Beat by an unspecified source, neither form factor of Apple Inc.’s (NASDAQ:AAPL) upcoming iPhone 6 is destined to feature a sapphire screen. The “source” simultaneously claims that the screens are not made out of Gorilla Glass by Corning, either, but some other, as yet unidentified material which is harder than Gorilla Glass but not as hard as sapphire crystal.
The fact that the Mohs hardness of substances is fairly easy to test lends some weight to this latest claim. Corning’s advanced Gorilla Glass 3, which the company compared favorably to sapphire in a 2013 advertisement, has a Mohs hardness of 6, while the Mohs hardness of sapphire is 9, the property which makes it immune to being scratched by steel. There is a fairly large gap between the hardness of Gorilla Glass 3 and sapphire, making comparative tests quite easy.
Assuming that Venture Beat’s source has an actual iPhone 6 and an iPhone 5 in hand, the data supplied to the news website is probably accurate. If the iPhone 6’s screen can be scratched by case-hardened file steel (Mohs hardness 7.5 to 8.5), then it is not sapphire (or, more precisely, corundum) crystal. If it simultaneously proves immune to scratching by quartz (Mohs hardness 7), then it is some substance harder than Gorilla Glass 3.
This, of course, begs the question of exactly what substance is being used for the iPhone 6’s screen. GT Advanced Technologies (NASDAQ:GTAT) has been delivering sapphire boules to Apple Inc. (AAPL) for months, using the production capacity of its Mesa, Arizona plant, and Apple in turn is presumably not purchasing these materials for no reason. There are also only a handful of companies globally which can handle the massive orders
Two speculative possibilities include that Corning or GTAT are, in fact, supplying Apple with displays made out of some unknown material. Analysts noted, for example, that Corning’s sales did not drop off despite the anticipated dent that Apple’s switch to sapphire would put in their revenue stream. Perhaps the resourceful company has made a new, much tougher variety of Gorilla Glass which is currently being supplied exclusively to Apple for the iPhone 6.
Alternatively, it might be that GTAT is not making pure corundum boules at its Mesa plant, but some proprietary, as yet unrevealed material with superior hardness to Gorilla Glass, but less hardness (and perhaps significantly less cost) than actual sapphire crystal. In both these scenarios, Apple (AAPL) could be planning a technological surprise without prompting the stir that would ensue if it went outside its normal supply channels.
