Vizja is right. Dragons have really thick scales, sometimes they happen to be shiny, but none of mine are. Metallics (copper, gold, etc) are just full of irid.
I see how it can be confusing -- at petsmart and places they always have really shiny betta's under dragon scales. Half of them arent even dragons, they just have a lot of metallic on them so they want people to pay more.
IN example::
See how on this guy you can see each individual scale looks really thick?

And with ths guy - you can see each scale, but its not as thick, just metallic