does the metallic sheen fade through time? i just got mine yesterday, in used but mint condition. the woman who i got it from used it a total of three times so the metallic is still very shiny like diamonds. but my friend just bought hers over to my apt so we could compare them, and hers (she had it for 8 months) is a bit faded looking. it still looks pretty but not as shiny like diamonds. is this normal after months of use?