updated 12:31 pm EDT, Thu June 19, 2014
Smaller facility may be purely for test production
Apple and GT Advanced have opened up a second sapphire manufacturing facility in Salem, Massachusetts, according to a filing submitted to the US Securities and Exchange Commission this week. GT already owned the 50,000-square-foot space in Salem, but has used part of Apple's recent $578 million prepayment to retrofit it with furnaces like the primary sapphire plant in Mesa, Arizona. Previously, the Salem complex was used as a research lab.
It's in fact unclear if the Salem building will be used to supplement Mesa production or just serve further test purposes. Rumors have hinted that the Mesa factory could double in size however, which may imply that GT needs to improve production wherever possible to keep up with Apple demand.
At this point, Apple has yet to explain the reason for partnering with GT. The company has been using sapphire glass in cameras and the Touch ID sensor on the iPhone 5s, and is expected to bring Touch ID to iPads and more iPhones this fall. Some analysts have suggested that it will have enough sapphire to cover iPhone and iWatch displays as well, but that could potentially be expensive.