In his latest video, YouTuber JerryRigEverything has tested the strength of the sapphire used by HTC on their limited sapphire edition HTC U Ultra and a $50 Zagg’s Sapphire defense curve screen protector for the Galaxy S8. 

For comparison’s sake, the YouTuber also had a Tissot watch featuring a sapphire glass at the front.

Unlike Gorilla Glass, Sapphire is scratch resistant to most objects that can easily scratch glass. Unless you regularly deal in diamonds, the chances of you scratching a sapphire glass are almost nil. While sapphire is more scratch resistant, it is more expensive and tough to manufacture which is why it is not widely used in smartphones and other electronic devices.

While Apple also uses sapphire camera lens on the iPhone 7 and iPhone 7 Plus, a previous video from JerryRigEverything had shown it to be easily susceptible to scratches. This was due to Apple using impure sapphire glass on the handset. Unlike Apple though, HTC has used the purest form of sapphire available to protect the 5.7-inch Dual Display of the U Ultra. Jerry only managed to scratch the display cover glass at a mohs hardness of 8 and 9, which makes the display on the U Ultra the most scratch resistant one he has ever tested.

As for that Zagg sapphire defense curve screen protector, it turned out to be a marketing gimmick and nothing else. Jerry was easily able to scratch it at a hardness of 3 mohs, which is even lower than the usual Gorilla Glass used on smartphones. And while sapphire does not catch fire, the $50 Zagg screen protector caught fire pretty easily. Essentially, despite Zagg’s marketing claims, its $50 screen protector is nothing but plastic and you really should not spend money on it.