In a new video that has surfaced, Apple Watch Sport's Ion-X display gets a scratch test that pushes it to the limit. Apple Watch Sport which has an Ion-X display (the 'Ion' meaning 'Ion-strengthened' glass) gets tested for its scratch resistance using small household things like a key, knife, steel wool and sandpaper. While the Ion-X glass display is not as strong as the sapphire crystal display in Apple Watch, it was expected to perform poor compared to the sapphire display. But, truth be told, that wasn't the case. The Ion-X display, incredibly, proved to be quite strong and resistant to scratches. It survived three of the four items that were used for scratching the display. Only sandpaper could leave a mark on the Ion-X display. The video was uploaded to Youtube by Unbox Therapy and uses Ion-X glass displays acquired from Sonny Dickson, the same person who acquires pre-release devices for testing. The Ion-X glass display performed impressive against key, knife and steel wool. All three items slid over the glass surface while only sandpaper could create an impact. However, even sandpaper could not leave the slightest of scratches behind on the sapphire glass on Apple Watch. This amazing scratch resistance of sapphire is the reason why all high-end watches use sapphire glass displays. Also, sapphire is quite expensive, meaning, Apple could not afford to use a sapphire display in its low-cost Apple Watch Sport editions. Apple Watch Sport is relatively cheaper compared to the Apple Watch. The starting price of Apple Watch sport is $349 compared to the $549 price tag for the entry-level model of Apple Watch.