9to5Mac was the first to put forth this hypothesis, reporting on an agreement between Apple and GT Advanced to produce up to 200 million of the displays in question.
Compared to traditional glass, sapphire crystal is far more resistant to breaking or scratches.
This makes the materials particularly suitable should Apple decide to equip its next iPhone with a slightly curved screen, as internet rumors have suggested over the past few weeks.
Production of the sapphire crystal displays could begin as early as this month, according to the website.
Apple already uses sapphire crystal in smaller quantities in a cover protecting the camera on the iPhone 5s.