Apple's decision to open a new factory in Arizona in partnership with mineral crystal firm GT Advanced Technologies is fuelling speculation the iPhone 6 will have a super-hard sapphire screens.
The special material is already used in the iPhone 5S fingerprint scanner and camera lense but not in the display as it is prohibitively expensive.
This is because sapphire is tough. Really, really tough.
it's used as shatter-proof windows in armoured vehicles and is the hardest natural substance next to diamond - it's virtually scratch proof.
This also means in order to cut and shape it you have to use diamond tipped tools, also a touch pricey.
Luxury mobile brands like the flashy but generally not very good Vertu already use sapphire - but they also cost a ridiculous amount of money.
It's hoped if more mainstream manufacturers use the material then the cost will go down with demand.
Apple currently uses Gorilla Glass, supplied by Corning which is cheaper but nowhere near as tough.
The new Apple factory will also be powered entirely by renewable energy and will create 2,000 new jobs.