Sapphire--it's not just for jewelry anymore. In the last few years, Apple has increased its use of the material in its products, and that trend seems to be on the upswing. On Monday, Arizona governor Jan Brewer announced that Apple will open a manufacturing facility in Mesa; that plant will be operated by GT Advanced Technologies, which will be providing sapphire for Cupertino's products.The plant will employ 700 workers and seems positioned to provide a lot of sapphire. Currently, Apple uses the material in relatively few places: It covers the lens on the iPhone 5c and 5s and is used as the top layer in the Touch ID sensor on the iPhone 5s. In both cases, it's harder and provides much more scratch resistance than conventional glass.By investing in a facility designed for the production of sapphire, though, it seems possible that Apple's expecting to nee
