When Corning ( GLW ) reported earnings last week, GT shares sank right away because Corning said that its Gorilla Glass -- Apple's current alternative to sapphire -- would grow sales by 20% next year. Even though Corning didn't say anything specific about Apple or sapphire, investors reacted to the news by selling GT because they concluded that any growth for gorilla glass must be bad for sapphire. Other analysts have worried that GT won't be able to produce enough sapphire in time for Apple to sell the iPhone 6 -- when it was released last year. So they expect two different iPhone release dates: one in September for a smaller iPhone 6 and one later in the Fall for the larger screen iPhone 6. It's expected among these analysts that GT will be able to produce enough sapphire for the later larger screened iPhone, along with the iWatch. There are other analysts who simply believe there are no sapphire production issues and GT will be fine to meet all of Apple's sapphire needs.