At one point in time, there were many rumors circulating suggesting that Apple could start adopting the use of sapphire for its displays. However that did not come true and so far the only places where sapphire is used is in select Apple Watch models and the camera lens on the iPhones.
Given that sapphire is meant to be a very hard material that is tough to crack, it is understandable that there are some iPhone X users who must be pretty miffed to discover how easily their camera lenses are cracking. This seems to be a growing problem where more than a few iPhone X customers have come forward to claim that the camera lenses are cracking, even without the phones being dropped.
Some have suggested that it is possible that the cold weather could be responsible for the lenses cracking, but at least one user from Malaysia writes that he/she is experiencing the problem as well. Apple has insisted in the past that the material used for the lens is indeed sapphire, so it is unclear as to what might be causing these cracks.
That being said, it seems that users who are affected cannot replace the device under warranty, and have been told that they will need to pay for a full device replacement, which last we checked was priced at whopping $549.