Smartphone screens have always been a shortcoming in overall durability. Picking up your phone, only to realize in that its face has sustained a web of long and deep scratches is a familiar horror story. Even gorilla glass is easily scratched by pocket sand. Thus, the idea of sapphire screens was born.
The second strongest material after diamond, its rumored use in the next iPhone promised extreme scratch resistance. Yet, the deal between Apple and GT Advanced never worked out – Ion-X remained the protector of iPhone 6s display. Here is the low-down on the successes and pitfalls of sapphire against Gorilla Glass.
Sapphire is much more expensive to manufacture than Gorilla Glass. This is a major shortcoming that caused the deal to fall through. Per square inch, glass costs a nickel or so, while sapphire costs several dollars. This stems from the fact that manufacturing the crystal is much more difficult, involving high temperatures and very low yields. Gorilla glass, in comparison, is much easier to manufacture in large quantities.
Another part where sapphire fails to hit the mark is in its transparency. Sapphire, like diamond, has a high refractive index. This causes issues like internal refraction, which in turn results in glare and reduced transmission. In effect, sapphire displays will seem shiny and hard to see. Whereas, Gorilla Glass has no such problems.
3. Scratch Resistance
This is one area where sapphire trumps Gorilla Glass. Sapphire is the second hardest material, with a 9.0 on the Mohs hardness scale. On the other hand, Gorilla Glass has a relatively modest 6.8. This means that sapphire is near impossible to scratch, while gorilla glass is easily marred by sand and dust. You can place sapphire-screen phones anywhere you like without worrying that it will scratch. Gorilla Glass is still hard enough to resist scratches from knifes and keys, though.
A strong glass is not one that has scratch resistance alone. In this department, Gorilla Glass reigns supreme. Sapphire, while hard, is very brittle due to its inability to flex. Phones with sapphire displays are hence more likely to shatter when dropped. The newest Gorilla Glass from Corning can flex a lot before breaking – something sapphire can not do. You still have to be careful with dropping phones with sapphire on it.
A quality screen should encompass more than scratch resistance alone. While having a scratch-proof screen is excellent for worry-free usage, too many tradeoffs have to be made for sapphire to be practical. Gorilla Glass remains the king for that reason – practicality. Sapphire cannot be mass produced easily without severe environmental penalties, and even so, living with a cracked screen is far worse than living with a scuffed one. In all, Gorilla Glass is arguably the better smartphone screen.