Earlier this week we got a look at what appeared to be the unbreakable sapphire glass cover Apple is expected to use for its iPhone 6. Now one expert in the material is stepping forward to confirm the rumors, claiming Apple consulted him about using a sapphire display over a year ago.

Speaking to The Guardian, Professor Neil Alford says he was one of multiple materials experts to meet with Apple last year to discuss the use of sapphire glass for a future iPhone. After watching a recent video showing the leaked front panel in action, Alford said it “could well be” the real thing. He added that the decision to use sapphire is “quite cunning,” noting that it’s the third hardest mineral known to man.

There are some drawbacks to using sapphire glass, mainly related to the production process. The material is expensive to produce and can only be cut up using diamond slicers. Apple recently started producing its own sapphire at a facility in Arizona, and hopefully the company has figured out a way to keep costs down.

If the iPhone 6 does feature a sapphire glass display it could be near-impossible to scratch or crack, giving Apple a huge advantage over the competition. Alford also notes that the Cupertino company is likely to patent its sapphire manufacturing process, giving it a large window of time before other companies can catch up.