NEW YORK (TheStreet) -- Shares of GT Advanced Technologies  (GTAT) plunged 11.25% to $15.22 in afternoon trading Tuesday after Apple  (AAPL - Get Report) announced its new iPhone 6 and iPhone 6 Plus would not feature sapphire displays.

GT Advanced Technologies makes sapphire displays, which many investors expected would make up the screens for the new Apple phones. But the tech giant said at its news conference Tuesday that the new displays would be "ion strengthened" and made no mention of sapphire displays for the phones.

The Apple Watch, however, will feature sapphire displays.

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More than 29.3 million shares had changed hands as of 3 p.m., compared to the average volume of 9,503,060.

GTAT Chart GTAT data by YCharts

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