Apple Inc. is reportedly developing sapphire display screens for its upcoming iPhone 6.

The Cupertino, California-based company is teaming up with GT Advanced Technologies to replicate the properties of sapphire, one of the hardest minerals on earth, according to the Wall Street Journal. Sapphire is strong enough to withstand high temperatures, as well as chemical corrosion.

The iPhone's first sapphire screens will be made at a factory in Mesa, Ariz., and are expected to be completed this month. Eric Virey, a senior analyst at French research firm Yole Developpment, said that once operating at full capacity, the facility will be able to produce twice the amount of sapphire than most manufacturers around the world.

Synthetic sapphire has only been used on certain occasions due to the cost of making it, the Wall Street Journal reported. The material is currently used in airplane windows and armored vehicles to deal with extreme conditions, as well as in watches to protect the device against scratches.

Protecting phone screens would be just another use of sapphire for Apple, as the company already uses the material for making sure the iPhone's camera lens and fingerprint reader aren't damaged.

While sapphire is scratch-resistant, its strength depends on its thickness and cut, which puts its ability to keep screens safe from breaking into question, the Wall Street Journal reported. The material can also make devices heavier since it is more dense than glass.

Apple is investing more than $700 million in developing the sapphire displays, and it plans to put them on premium versions of the 4.7-inch and 5.5-inch models of the iPhone 6, Yahoo! News reported. The screens would be added this fall, if the company is able to obtain the necessary supplies.

Creating displays that are stronger than the iPhones' current Gorilla Glass material will provide the opportunity for Apple to save money.

"Before the Apple investment, I would have said sapphire is a great material with great potential but it's a few years out from becoming a market reality," said Vinita Jakhanwal, HIS Technology's director of mobile and emerging display technologies. "But Apple has invested a significant amount, so it would be fair to say that the company probably expects a return on its investment pretty quickly."