One of a kind natural Australian opal doublet. Bezel set in sterling silver with 18" sterling silver box chain.

What is an opal doublet? A doublet is a stone made of two materials: the first is a natural sheet of gemstone, like solid opal, and the second is a solid backing, like ironstone. An opal doublet isn't made from 100% opal. Instead, a piece of solid opal is attached to a different material backing.