Venetian Estate 18K Yellow Gold and Polished Rough Cut Boulder Opal Necklace. Necklace measures approximately 17" long. Largest boulder opal measures approximately 3" long x 1 1/4" wide, and opals decrease in size graduating to the back of the necklace. "S" hook closure. Necklace can be worn on the neutral, brown "ironstone" side for an optional look.