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Sapphire Glass Didn't Pass iPhone Drop Test According to Reports
SternisheFan notes reports about why Apple didn't use sapphire glass screens in the latest iPhones as many expected. Sapphire screens were part of the iPhone 6 design until the glass repeatedly cracked during standard drop tests conducted by Apple suppliers. So Apple abandoned its sapphire plans before the iPhone 6 product launch September 9. VentureBeat has learned that recent supplier channel checks by an IDC analyst yielded several reports of the sapphire failures and Apple's decision against using the glass material. As we heard on Tuesday in Cupertino, both the iPhone 6 and the larger iPhone 6 Plus will ship with screens made of "ion-strengthened" glass. This was apparently Apple's second choice. IDC analyst Danielle Levitas says it isn't clear when exactly the drop-test failures took place, or when Apple abandoned plans for sapphire-screened iPhones. She says the poor drop-test results, combined with the relative high cost of sapphire glass, could have made plans to ship sapphire glass phones too risky. One researcher who covers GT Advanced Technologies, the company that was to produce the glass for the iPhone 6, wrote in a research note earlier this week that plans for the sapphire screens were cancelled in August, just weeks before the September 9 launch. The new Apple Watches (except the "Sport" version) do use sapphire for their screens. Levitas believes that the glass for the smaller 1.5-inch and 1.7-inch watch screens was less likely to break in drop tests.
Company tries two things, chooses the one that is better. News at 11.
CNET also covers this well, noting SapphireGlass costs $30 per unit versus $3 for Gorilla Glass. From the CNET article...
Corning, which has repeatedly criticized the use of sapphire as a mobile-device display, says its testing found that though sapphire is harder to scratch than its Gorilla Glass, daily use of a sapphire display will produce tiny cracks in the material. Those cracks can easily proliferate and cause the display to break more easily over time than Gorilla Glass. As a major manufacturer of industrial crystals, Corning should know a thing or two about sapphire. It used to make tubes of it for high-temperature lighting during the 1960s and 1970s, according to Jeffrey Evenson, Corning's operations chief of staff.
"As material guys, we think Gorilla has a lot more potential," Evenson said, who added that glass is much easier to manipulate into different forms, such as with the rounded Gorilla Glass display of the new Samsung Note Edge smartphone.
http://www.cnet.com/news/why-t...
No, regular hardened glass is tempered by quenching (heated in a furnace around 700C then quenched by rapid cooling)
Disclamer: I work in a glass factory.
One of the largest uses for artificial sapphire is supermarket barcode scanners. No one's putting it there because they feel a need to bling-out the supermarket. It's there because any surface that has stuff dragged across it all day, every day either needs to be incredible scratch-resistant or replaced way too often.
The glass consists of a thin sheet of alkali-aluminosilicate. Gorilla Glass is strengthened using an ion-exchange process which forces large ions into the spaces between molecules on the glass surface. Specifically, glass is placed in a 400C molten potassium salt bath, which forces potassium ions to replace the sodium ions originally in the glass. The larger potassium ions take up more space between the other atoms in the glass. As the glass cools, the crunched-together atoms produce a high level of compressive stress in the glass that helps protect the surface from mechanical damage.
http://chemistry.about.com/od/...
How Sapphire Glass is made...
http://www.businessinsider.com...
http://www.corninggorillaglass...
Actually it's not. Moissanite (silicon carbide) is harder. 9.5 on the Mohs scale, vs 9 for sapphire/corundum, 10 for diamond. Its structure is the same as diamond, except it alternates between silicon and carbon atoms, the silicon-carbon bond being nearly as strong as a carbon-carbon bond. I first ran across it (as an opaque conglomerate of smaller crystals) as guides for fishing rods - the hardness prevents braided lines from gouging a groove in the guide. There are a bunch of other materials harder than corundum, but I believe moissanite is the only transparent one.
Remember what your momma taught you - never trust a salesman.
No, Apple didn't hype it, and never announced that they would use it on the phones. Lots of rumour sites saw apple buying a sapphire glass manufacturing company, and decided that 2+2=9.