A report from Taiwan’s Apple Daily purports to show an assembled iPhone 5C, the low-cost iPhone rumored to be announced on September 10, surviving an informal pocket test with no visible scratches on its rear plastic shell. In it, an anonymous individual puts the 5C into a gallon Ziploc bag with coins, keys, screws, paper clips and, what appears to be a pocket flashlight, then closes and shakes the bag vigorously.
After the shake test, the person drags the keys, screws and coins across the surface of the plastic shell in an attempt to scratch it. After putting the pink 5C through its paces, the reflection on the rear of the shell shows no visible scratches whatsoever, at least at the video's resolution. The implication is that Apple's may have used a new process to make the plastic extremely scratch-resistant.
Apple faced numerous complaints (and a class-action lawsuit) in 2005 because of how easily the original iPod nano's plastic surface sustained scratches. In August 2010 Apple acquired LiquidMetal and its new metallic/glass substance that has twice the strength of Titanium but the moldability of plastic. Then, in late 2010, Apple filed a patent application for "Nitriding Stainless Steel for Consumer Electronic Products" which resists scratches by placing a layer of nitride over a stainless steel exterior.
Don't be surprised if the iPhone 5C case is fabricated from nitride-coated LiquidMetal.
The video also shows some precise measurements of the device. Measuring 24.55mm x 59.13mm x 8.98mm in the video, the iPhone 5C comes in at slightly larger than the iPhone 5.