Apple would have tested the glass in “synthetic sapphire crystal” for its screens

From the iPhone 5, Apple uses synthetic sapphire crystal for
Protection of the APN objective.

Since then, we had mentioned a rumor concerning theHome button from the future iPhone 5S that could
become tactile to integrate the fingerprint sensor and would be
precisely protected by a sapphire 'glass layer'.

We even saw that
Gorilla, to whom we owe the windows used on the iPhone and
iPad, sought to convince that his windows are more resistant than those in
sapphire.

Well

According to Perry Oosting, CEO of virtue, the British company producing the
famous luxury phones, Apple would haveexperienced screens in
sapphirre but experience would not have been conclusive.

Indeed, the materialis expensive to produceand it would be
very difficult to produce in large quantities, conditions
Unacceptable for Apple which sells its products by millions.

Thus, we should have a glass screen Gorilla again on the
Next Apple terminals

Response in a few months with the announcement of theiPhone 5S.

source