Apple advertises the Watch as having two distinct displays with the Watch Sport including an Ion-X display and the other models, the Apple Watch and Watch Edition, shipping with a sapphire glass screen. To be clear, these two materials do not comprise the entire display, but instead are the outer covers that protect the underlying flexible Retina display. Why did Apple decide to use two different display matrixes and what are the difference between the two materials? Read on to find out.
Apple chose two different display materials based on how each device is meant to be used. While the Apple Watch and Watch Edition likely will be used as timepieces first and fitness trackers second, the Watch Sport will be used first and foremost as a fitness device. As a result, Apple has designed the Watch Sport to be the lightest model in the Watch lineup and the version most able to withstand the impact of physical activities.
The Watch Sport will ship with an aluminum casing that shaves up to 30 percent off the weight of the device and an Ion-X glass display that is lighter than sapphire and contributes less to the overall weight of the device. The Ion-X material is an aluminosilicate glass that is “fortified at the molecular level through ion exchange, with smaller ions being replaced by larger ones to create a surface layer far tougher than ordinary glass.” This process creates a material that is resistant to both scratches and impact, which is a major advantage over sapphire glass.
Sapphire is an ideal matrix for a watch and traditionally has graced the cover of luxury watches. Sapphire is very hard, second only to diamond on the hardness scale, and is extremely resistant to scratches. It also has a crystal clear transparency that makes it ideal for screens.
Sapphire’s Achilles heel is its brittleness, which makes it prone to fracturing on impact. This impact sensitivity is why Apple likely included sapphire in the Watch models that people will wear for fashion and not for fitness. This brittleness also allegedly is one of the reasons Apple last year abandoned sapphire for its iPhone models.