Shop › Boulder opal ring Image 1 of 2 Image 2 of 2 Boulder opal ring A$490.00 sold out Solid Queensland boulder opal, set in 9ct yellow gold, shank made in sterling silver. Lovingly handmade in Melbourne. Sold Out Added! Solid Queensland boulder opal, set in 9ct yellow gold, shank made in sterling silver. Lovingly handmade in Melbourne.