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It is made of glass and very durable. I do not think it would withstand as much as the iPhone though.

I know you didn't ask this, but the screen res, sharpness, and colours are superb.
 
Are you sure it's glass? This review says it's still plastic.

With the same 320-by-240-pixel resolution as the screen on the iPod classic, the nano’s display features the highest pixel density of any display Apple has ever produced and the screen is also 65 percent brighter than that of the previous nano, according to the company. However, it’s made of the same material as that of previous iPods, rather than the more-durable optical glass used on the iPhone and iPod touch.

I really hope they are wrong, though :).
 
Yeah it's plastic. I watched a torture test of the nano and they scratched it very easily with a key.
 
It is plastic, like the mini, 2G nano and classic (all the aluminum iPods), but it is much more scratch resistant than any of the plastic fronted iPods. It will not scratch in your pocket unless you put keys or coins or anything else like that in there with it.
 
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