Metallic Blue Berries! Pollia condensata "Marble Berry"
"Marble berries" display the shiniest biological phenomenon in their metallic blue skin! Their coloring derives from structural coloration - similar to that employed by Morpho butterflies in their wing scales. Structural coloration is not pigmented, rather it is a method by which minute physical structures are used to limit light wavelengths to specific chroma frequencies. For more information see: Pollia condensata
I've gathered a few images from around the web showing how beautiful these berries can be!