Apple iPhone 6’s much hyped display, which reportedly survived the most torturous stress tests, may not be sapphire crystal after all, claims a new report.
A video posted on YouTube by Marques Brownlee shows that the display can get scratched when it comes in contact with sandpaper. Two types of sandpaper were used during the test – garnet and emery sandpapers – with the display coming out scratched.
Brownlee also uses the Mohs scale of relative hardness to explain why the display might not be made of sapphire crystal. Sapphire is rated 9 on a scale of 10 on the Mohs scale while the garnet sandpaper scores a 7 and emery, an 8. The basic reason for his conclusion is that any material that is rated higher cannot be scratched by a material with a lower rating.
When the same test was performed on an iPhone 5s, the screen got scratched, however, the home button which also functions as the Touch ID survived the test. Apple uses sapphire crystals for manufacturing the Touch ID home button.
It leads to the conclusion that the display which is allegedly destined to be fitted on the 4.7 inch iPhone 6 is not sapphire. However, the 5.5 inch model might get a sapphire display.
Sources also note that one of Apple’s recent patent filings describes a sapphire lamination technique to create a “composite involving sapphire”. The patent also talks about a fabrication method that makes the product capable enough to overcome the tests shown in the video, also making it flexible and impact-resistant.
However, Apple’s plans for the display of its upcoming devices, speculated to launch by this fall, remains to be unknown.
MKBHD also notes that the fact that it is not entirely sapphire glass is probably good: it resists shattering better, while still having better scratch protection than Gorilla Glass bc of the sapphire it does contain. Pure sappphire would shatter much more easily than a composite.