GT Advanced Technologies Inc fka GTAT

[Netsurfer]

The 2000 furnaces are essentially the same as the ones in Salem NH and those were primarily used to grow Sapphire for LED substrates and some optical applications..lenses, windows and lasers. Salem was aka Crystal Systems and that tech team was primarily responsible for the scaling activity to 262Kg.
The original systems were in the 100Kg range I believe.
These boules need to be cored 90 degrees to the growth axis to get C plane sapphire for LED's so there is a lot of waste material. Arc Energy grows theirs such that the C axis is the growth axis so there is in concept less wasted material.
Arc is very small and privately held but have crystal growth experience from Crystal Systems and St. Gobain.
Not sure which plane the phone windows were going to be but Apple did have a patent for a laminated window that used both C and R plane sapphire.