Reticulated silver and Opal ring

There is just the one of these ever  and it's a size U. 
This Opal is gorgeous, it's quite an unusual colour for an Australian Opal doublet, the pictures aren't really doing it justice. It's similar to a duck egg blue and has stunning green fire when it catches the light.
The rectangle is 15x20x1.5mm and the ring is 2.5mm and brushed matte.