This boulder opal pendant is handcrafted from 14K/20 gold filled wire and a boulder opal cabochon (cab) from Queensland, Australia. There are no color plays in this stone, just a very calming, water-like scene. I really like this stone. Sometimes it looks more blue, and sometimes more grey, but always very serene. 14K/20 gold filled wire is basically a tube of 14K gold with a jeweler’s wire down the center for flexibility. It wears well, does not tarnish, and has the same allergy reactions (or non-reactions) as 14K gold. Each of my cabochon pendants are "one-of-a-kind" and you are selecting the actual one you will be receiving. The chain is not included, but I do have a selection of chains if you need one. approximately 3/4" x 2 1/4" 19mm x 57mm 9mm bail