Apple iWatch Sapphire
The Apple iWatch display may use a sapphire screen cover Reuters

Following in the steps of its larger sibling, the highly rumored Apple Inc. (NASDAQ:AAPL) iWatch will also have an “indestructible” sapphire screen cover.

The Wall Street Journal reported on Thursday that the first sapphire screens for the rumored iPhone 6 and the iWatch are expected to come of production lines this month from a Mesa, Arizona factory jointly operated by Apple and Merrimack, New Hampshire-based material producer, GT Advanced Technologies Inc. (NASDAQ:GTAT). The plant reportedly will be able to manufacture twice as much sapphire as current synthetic sapphire producers around the world.

Sapphire, a material known for its scratch- and crack-resistant properties is one of the hardest materials on earth. While its properties are ideal for making increasing durability, high manufacturing costs have left it mostly unsuitable for large-scale mass production applications, relegating sapphire to select items, such as covers for luxury watches.

Apple currently uses sapphire for the iPhone camera lens and its Touch ID fingerprint reader and is also expected to use the material in the screens of its rumored mobile and wearable products. But reports indicate that Apple may reserve the material for use in high-end iPhone 6 devices, including the larger 5.5-inch model.

As sapphire display cover rumors continue to float around, competitors have taken shots at the material for being a less suitable material for display covers compared to Corning Inc.’s (NYSE:GLW) Gorilla Glass. While opinions differ on whether or not the material is ideal for large display use, it has already proven its worth in smaller applications with its use in luxury watches.

With Apple bringing in executives in the past year from high-profile luxury brands such as Tag Heuer’s Patrick Pruniaux and Burberry Group’s (LON:BRBY) Angela Ahrendts, Apple could position the iWatch as such a luxury item.

But, until it’s unveiled, nothing is certain. Apple will reportedly unveil the iWatch sometime in October following the Sept. 9 media event for its rumored iPhone 6.