An interesting new video posted by JerryRigEverything compares the sapphire lens cover protecting the iPhone 7 camera lens to the same material used on traditional watches.
A different league?
In the video, both are subjected to some scratch tests to determine their true hardness.
The watch cover only begins to scratch with a No. 8 pick on the Mohs Scale of Elemental Hardness. The material protecting the camera lens of the iPhone 7, iPhone 6, iPhone SE, and iPhone 5s begin to scratch with a No. 6 pick meaning its not as hard as what is found on the watch.
In conclusion, the video surmises that the Apple lens cover is made from a sapphire laminate. That means a thin layer of sapphire material is placed on top of the glass as a cost savings measure.
Interestingly, the channel didn’t test out the hardness of the sapphire cover found on more expensive versions of the Apple Watch. I’d definitely be interested to see if it was more similar to the Tissot cover or if its just a larger piece of the sapphire laminate.