Pollia Condensata has been declared the shiniest fruit on earth by the National Academy of Scientists. Most living things on earth reflect color by pigment but some things, like peacock feathers and scarab beetles, reflect light by structural means. In the case of Pollia the cellulose structures of the cell walls reflect blue light, thus giving them the shiny blue appearance. They don't have any nutritional value for humans but birds eat them because they are very eye catching. Because the color is produced by the cellular structure it does not fade after the plant has been picked. Each individual cell reflects the blue light thus making them appear glittery.
These plants are found in Africa in forested regions.
Maybe this fruit can lend scientific credibility to the shiny vampires of Twilight?