Tests say the sapphire used on the iPhones lens is less sturdy than usual, but Apple denies

A few weeks ago, we published here a general overview of endurance tests with the (newly released) iPhone 7. One such test from the YouTube channel JerryRigEverything, scratched every possible surface of the new device and detected a weakness in the camera's lens coating that even led me to write a warning to future owners of iPhones 7/7 Plus:

Be especially careful of the glass covering the camera lens, which was easily scratched.

Little did we know then that such a finding would be the trigger for yet another polemic in the world of Apple. First, right after the publication of the test, it was speculated that Apple would have abandoned the use of Apple. sapphire (the diamond-like material of hardness used on the screen of more expensive Apple Watches and the lenses and buttons of Home iPhones) on their smartphones, even stating in their list of technical specifications that, yes, sapphire is present in them.

Speculation has even been denied by Phil Schiller on Twitter:

Are these reports about the iPhone 7 not sapphire about Touch ID and / or camera lens true? # iPhone7

In fact. The lens cover and the top of the Home button are (made of) sapphire. # iPhone7

The questioning then subsided until a few days ago when Zack the YouTuber behind the channel JerryRigEverything, published another video going deeper into the material issue behind (or rather ahead of) the iPhone lens:

The extremely in-depth test began by comparing the sapphire of a Tissot brand watch that also employs the material as a coating with the one that covers the iPhone 7 camera. While the watch was scratched with only an 8th grade mineral on the Mohs Scale, the iPhone's lens protection was tarnished at grade 6, two earlier than acceptable, reinforcing doubts about the “legitimacy” of the sapphire employed there.

Here is a small addendum to the Mohs Scale, which is used to rate the hardness of materials: ordinary glass has grade 5 on this scale, while pure sapphire has grade 9 and diamond, the hardest material found in nature, has grade 5. 10 (maximum). That is, theoretically, under no circumstances could a so-called sapphire surface scratch with a hardness grade 6 mineral.

Not satisfied with the results, Zack took the iPhone lens to the lab and analyzed its composition with an electron microscope and a fluorescent X-ray machine. The video explains it in a very technical way, but to put it bluntly, the conclusion that Apple doesn't use pure sapphire on the lens of its smartphones, far from it: the material is a mix of a number of things, including aluminum and a It is a little sapphire that has its higher concentration on the outside (exposed) than on the inner portion.

In other words, the material used by Apple on the lens of iPhones is harder than glass, but not as tough as sapphire. At least what the test says, but guess what Apple claims otherwise. In an official press release released, Ma states:

Apple confirms that the iPhone 7 sapphire lens and, under appropriate test conditions, exhibits the expected hardness and clarity of the material.

Going further into this explanation beyond unsatisfying blogger Rene Richie of iMore, stated that, in fact, the iPhone lens is not being scratched in the test, but broken that what happens when something very thin, such as the lens, receives uncontrolled pressure in a very small area (in this case, the tip object used to “scratch” the material). After all, pressure = strength / area (if you still remember physics classes). 😝

The protection of the Tissot watch, on the other hand, withstood more breaking because it is much thicker, as Richie claims such a result can be seen in the video itself, when the YouTuber shows the "scratches" in the electron microscope. That is, after all, the tests could not be taken into account by the lack of technical rigor and specific conditions, say Apple and Richie. You are scratching it wrong.

In any case, be careful with the lens of your iPhone, do not expose it to diamonds or very hard materials on the Mohs Scale and use sunscreen. In you, in the case.

(via The Verge)