Over the past couple of weeks, YouTubers have been conducting all kinds of "tests" on the new iPhone 7 and iPhone 7 Plus, looking for flaws, confirming Apple's design claims, and exploring new features. One test on the sapphire cover of the rear-facing camera, calls into question whether lens cover is indeed made of sapphire after it's shown being scratched with picks designed to emulate the Mohs hardness scale.
On the Mohs scale of hardness, sapphire rates a 9, coming in just under diamond at a 10 on the top of the scale. Its hardness makes it resistant to scratching, and so it's used by high-end watch makers and by Apple to cover the Home button and the rear camera of the iPhone 7.
In the video, scratches are made on the iPhone 7 camera and a sapphire-equipped Tissot watch using specialized Mohs tools. With a pick the reviewer claims is "Mohs 6," he is able to make scratches on the camera lens, theorizing that it is made from sapphire-laminated glass or impure sapphire because sapphire should resist scratches at Mohs 6.
This test, and others like it, have caused people to claim that Apple is lying about using pure sapphire crystal over the camera lens, prompting the company to release an
official statement subtly calling into question the testing methods used in the video. The reviewer does use tools to determine the composition of the sapphire and finds carbon, but it is not clear that the test was done without contamination.
Apple confirms the iPhone 7 camera lens is sapphire, and under proper testing conditions, achieves the hardness and purity results expected from sapphire.
Last month, Apple's Phil Schiller also confirmed on Twitter that the rear lens cover on the iPhone 7 and the iPhone 7 Plus are constructed from sapphire.
According to
iMore's Rene Ritchie, there's a simple explanation for the discrepancy between Apple's claims and what's going on in the video. The tools used in the video aren't scratching the lens -- they're causing fracturing, as can even be seen when the sapphire is placed under the microscope, due to heavy pressure.
Fracturing -- as opposed to scratching -- is what happens when you have something so incredibly thin -- unlike the much thicker watch used for comparison -- and you apply pressure with no level of control.
You'd have to precisely apply the same level of force, likely to the same thickness of material, to properly do that test.
Apple has used sapphire crystal for iPhone components for multiple years and maintains that sapphire crystal continues to be present in the iPhone 7 and the iPhone 7 Plus, a conclusion that was also ultimately reached in the video.
Top Rated Comments
(View all)Rene Ritchie, the definition of an Apple fanboy.
What, he's an Apple fanboy for citing the scientific reason why it scratched?
God forbid living in a world constrained by the laws of nature.
Still won't stop the naysayers. I believe the reason why the camera scratched so easily is because there is a coating on it.
well, doesnt' that kind of defeat the purpose of using sapphire then? the Sapphire is desired because of it's anti-scratch resistance. If they're just going to put a coating on top, that is more scratch prone, you've now just lowered your scratch resistence to the point of the coating, not the sapphire.
Point is, the lens isn't going to scratch under normal scenarios when coming into contact with most objects.
Speak for yourself. I frequently carry a diamond pick and blowtorch in my trouser pocket.
I don't think that Phil Schiller or 'iMore's Renie Ritchie' actually know what sapphire is.
If not sapphire (what one commonly expects it to be), this would be close to fraud. It doesn't really matter if one can still claim whether this aluminum oxide can still be called sapphire, for me what counts is the property people expect when they read 'sapphire' and that is HARDNESS!!!! Phil Schiller could sell sewage water as 'bottled water' yeah, but it wouldn't really be what people would expect. If you read 'sapphire' you buy it for it's hardness. If Apple-Sapphire is not as hard as the material everybody knows as 'sapphire' .... well.... dishonest/greedy... or incompetent.
....... DELETED
I can promise you one thing. The second I get my hands on an older/broken iPhone, I will analyze it with the state of the art equipment I have at my disposal at work (1. Nanoindentation = proper hardness measurement, 2. XRD = x-ray diffractometry for crystallinity check). So if anyone has a spare part flying around, just message me, I can do this any day.
My hunch is, that whatever apple calls this, it isn't nearly as hard as what everybody expects when they hear SAPPHIRE and that is what truly counts!
edit:
The EDS spectra he shows are not sampled right. Thanks to the lab assistant that forgot to explain to him - or him for misinterpreting. They say 'Map Sum Spectrum' and if they're from the maps he showed it is obvious where the silicon and carbon signals are coming from!!!! The coating on the inside of the coverglass! He needed to measure just the bulk material with a spot-sample in order to get the correct spectrum and my guess now is:
- EDS done wrong --> bulk material actually pure aluminum oxide (crystallinity & hardness still unknown)
- Hardness test scratched a second anti-reflection coating on the outside which is less hard (SiNx, SiCx, SiOx, MgF... whatever). This one is too thin to be seen using EDS --> ZOOM IN more using the SEM or use ellipsometry!
I will test this myself in time and we will see.
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