Meet the Mirror Spider, a spider with shiny guanine crystal patches on its back that give it the appearance of the broken glass mosaic you made in arts & crafts class. The shiny parts appear small when the spider.
The Mirror Spider (Thwaitesia sp.) has an abdomen covered in reflective silver 'plates'. What's fascinating about these plates is that when the spider moves, they contract; after a period of resting they dilate again to cover the entire abdomen.