In Pictures: Here’s how Apple is spending $1 billi...
The Mesa, Ariz., production site is equipped with the Advanced Sapphire Furnace (AFS, show here), from GT Advanced Technologies. These GTAT furnaces use a variation of what's known as the Czochralski melt-growth process: it combines melting with directional cooling to create a very large sapphire crystal of very high purity.
Shown: ASF units online at GTAT's sapphire R&D and production facility, Salem, Mass.
In Pictures: Here’s how Apple is spending $1 billion on sapphire