Apple signed a deal with GT Advanced Technologies to create sapphire displays for the iPhone 6. Trusting an unproven supplier proved to be a fatal mistake, one that the Cupertino-based company likely won’t repeat anytime soon. A week ago, news surfaced that longtime manufacturing partner Foxconn was planning to spend $2.6 billion over the next two years to build a new display manufacturing plant. Although Foxconn didn’t reveal much about the plant, a spokesperson said that it is being built at the urgent request of a client for exclusive use.