why are metals shiny in appearnce?

Answer 1

Probably has something to do with the latticed structure of the molecules. Things with lattice structures to them often shine (like crystals and glass, etc).

Answer 2

I think the shine is from the reflectance of all colors of light at once, not just one color. Get a pair of polarizing sunglasses and look at trees and lakes. When you turn then just right, the trees get very, very green looking, because the polarizing is eliminating the shine, leaving only the green. Go look up Brewster's Angle in wiki.