Apple's Use Of 'Sapphire' in iPhone Camera Lens Questioned in New Tests (theverge.com)

An anonymous reader writes: Apple has been using sapphire on its iPhone camera lenses for a few years now since the launch of the iPhone 5S, but it might not be as scratch resistant as you'd expect. A new video raises questions over Apple's use of sapphire in its iPhone camera lens, and includes scratch tests to rate its durability. While Apple claims it uses sapphire crystal in its iPhone lens, tests by YouTuber JerryRigEverything show that Apple could be using a more cost effective sapphire laminate on top of regular glass. JerryRigEverything tested Apple's iPhone lens with an XRF machine and electron microscope, and concluded that Apple doesn't use pure sapphire in its lenses. The underside of the lens contains less sapphire than the exposed part, and a scratching comparison with a Tissot sapphire watch showed that the lens cover will scratch at a level 6 on Mohs Scale of Hardness, compared to level 8 for the Tissot watch.

Comments

Re: Amazing!

[Anonymous Coward]

Sapphire is 9 on Mohs scale. If they measured 6, then it is ordinary lens glass.

Re:And yet, consumers are silent.

[Shimbo]

Other than perhaps a Kardashian, no one is carrying around diamonds in their pockets to scratch their pseudo-sapphire iPhone lens.

If it is only 6 on the Mohs scale it means that it will be scratched by quartz, so if you have dirt in your pocket it may get scratched.

Re:Sapphire crystal lens cover

[GuB-42]

The problem is that when you try to scratch the front side, the force transfers to the back side and cause a visible and permanent scratch even though the front side stays smooth. It is shown in the video.

Re:Just a hunch

[sl3xd]

I don't think optics would be the problem: It's impact resistance. While it's great for scratches & abrasions, sapphire is easy to shatter & crack.

When you have a lens that sticks out of the phone, impact resistance is probably something to consider.

Re:Hard enough?

[morethanapapercert]

Keys aren't commonly made of steel and haven't been made of iron since the abandonment of skeleton keys for general use. Most keys are brass or aluminium with both being ~ a 3 on the Mohs scale. ( I use Mohs here because we're talking about contact with alleged sapphire and gemstones are usually rated on the Mohs scale, not Brinnell, Rockwell or Vickers) Thus a key should just skate across a smoothly polished screen surface if it indeed sapphire. In fact, if there are existing scratches on the screen glass, those scratches should mark the key!

There are two caveats though:

1) This only accounts for the keys themselves, not the spring steel keyring that is almost universally used to organize keys nor any keychains, fobs or charms.

2) There are several aspects lumped together under the term "hardness", scratch resistance, rebound hardness and resistance to deformation under a static load. A materials rating under the Mohs scale doesn't cover all of that, so only gives you one part of the picture. And as far as I know, no general purpose hardness test covers glancing/gouging impacts where the velocity of impact is as an equally important component of the tests. A straw can embed itself in wood if it's going fast enough after all. (velocity of the impacting object IS quite important in armour testing, so those tests are careful to take speed and angle of impact into consideration.