Apple iPhone 6 Display May Not Be Pure Sapphire

An iPhone made out of sapphire may, in fact, be too good to be true.

Apple Inc. (NASDAQ:AAPL) is expected to use a tougher sapphire glass for its display for the iPhone 6 display; however, the display may not be 100 percent sapphire.

YouTube content creator Marques Brownlee in early July shared details of the iPhone 6 sapphire glass display, having supposedly obtained a 4.7-inch iPhone 6 screen panel. Brownlee, 20, reportedly did a series of durability tests on the panel, demonstrating how the glass could be bent, scratched, scraped and stabbed with a knife or keys without being damaged. London Imperial engineering professor Neal Alford then told Britain's Guardian he believes the panel is made out of sapphire.

Brownlee's demonstration, however, may have been flawed. In a new video, he explained that the knife and keys used to scratch the display panel were too soft to cause any damage. He referred to the Mohs scale, which measures the hardness and scratch resistance of various minerals, from 1 as the softest mineral, to 10 as the hardest. According to the scale, a mineral can be used to scratch any mineral with a lesser rating, while that mineral can be scratched by any mineral with a greater rating.

“The softest mineral on the scale is talc rising to quartz at No. 7 and diamond is 10," Alford told the Guardian on Monday. "Corundum, which is sapphire, is No. 9.”

Brownlee also demonstrated a scratch test on the display panel as well as on an iPhone 5s, using garnet and emery sandpaper. The display on the iPhone 5s is made of Corning Inc. (NYSE:GLW) Gorilla Glass, which is about a 6.8 on the Mohs, while garnet sandpaper rates about a 6 and emery rates about an 8.

The iPhone 5s display was significantly scratched by both sandpapers, but especially by the much harder emery. The purported iPhone 6 display panel did show some scratches from both sandpapers, but not as much as the iPhone 5s display. This has led Brownlee to believe that the display may actually be some sort of sapphire glass blend.

“Using a massive panel of pure sapphire for the front of a phone would be a little bit stupid,” he said in the video. “It would be much more expensive and it also wouldn’t be able to bend like it did. Believe it or not, you need your phone to be able to flex a little bit.”

Brownlee noted that pure sapphire is best used for such small components. Apple uses pure sapphire in various iPhone parts, including camera lenses and Touch ID home buttons. The small sapphire parts provide high quality and durability, and also ensure accuracy for the iPhone features, with which they correlate, it has said. A scratch test with the emery sandpaper on the sapphire glass cover on the iPhone 5s Touch ID resulted in no scratches (sapphire is harder than emery).

Apple already has patents for two sapphire lamination techniques, which fuse sapphire with other materials, Alford told the Guardian. One patent is for a technique that fuses two different cuts of sapphire together, while the other technique fuses sapphire to glass made of quartz or silica.

A sapphire glass blend display could still affect the price of the iPhone 6 display. Reports from several analysts suggest that Apple may use its sapphire display only in the high-end iPhone 6 models, citing supply issues for the mineral. The iPhone 6 is expected to be available in 32GB and 64GB versions; smartphones with larger memory capacities tend to be more expensive. For example, there's a $100 difference in price between the 32GB iPhone 5s and 64GB model. Some analysts believe the new high-end iPhone 6 models may even come in a version offering 128GB of internal memory -- and they said the 64GB and 128GB versions most likely would have a sapphire display, potentially pushing their prices up.