Apple is making a billion dollar bet on sapphire as a strategic material for mobile devices such as the iPhone, iPad and perhaps an iWatch. Though exactly what the company plans to do with the scratch-resistant crystal and when is still the subject of debate.
Apple is creating its own supply chain devoted to producing and finishing synthetic sapphire crystal in unprecedented quantities. The new Mesa, Ariz., plant, in a partnership with sapphire furnace maker GT Advanced Technologies (GTAT) of Merrimack, N.H., will make Apple one of the world's largest sapphire producers when it reaches full capacity, probably in late 2014. By doing so, Apple is assured of a very large amount of sapphire and insulates itself from the ups and downs of sapphire material pricing in the global market.
In keeping with long-standing practice, Apple has never publicly discussed the Arizona project or what it intends to do with such a vast amount of sapphire material. Rumors and more or less informed speculation have flourished in that silence.
The Arizona project was revealed in November, with Apple paying $578 million for GTAT to install and run its advanced sapphire growth furnaces in a plant built and owned by Apple. The news triggered a frenzy of speculation that Apple planned to use sapphire crystal sheets to replace the glass currently used in touch displays for its 2014 iPhones, iPads or a new line of "wearables" such as the long-rumored iWatch, or all of the above.
That's only the tip of Apple's investment. Once the 253-pound "hockey puck" shaped sapphire boules emerge from the furnaces, they'll be shipped to Apple's supply chain partners in Asia, including Biel Crystal Manufactory and Lens One Technology Co., for slicing, polishing, laser cutting, coating and eventual assembly.
But to do all this, these companies, and Apple, will have to invest heavily in new equipment that can handle sapphire, since only diamond is harder, and handle it in the quantities that Apple will produce. That's not a simple process.
Natural sapphire is a gemstone variety of the mineral corundum, a crystalline form of aluminum oxide. Corundum is colorless, but in natural sapphires, various impurities create a range of colors: chromium makes the gem red, becoming a ruby; iron and titanium create the prized cornflower blue of a true sapphire.
Synthetic sapphire is colorless, unless deliberately colored. GTAT's ASF uses a variation of what's called the Czochralski process, combining the melting of aluminum oxide, a seed sapphire crystal, and heat extraction to crystalize the alumina melt. [For more details, see the accompanying slideshow: "Why Apple's sapphire plan is as hard as the mineral itself"] Like natural sapphire, the synthetic is incredibly hard and that hardness creates challenges for using it.
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