Opal and green onyx with silver findings, chain, and centerpieces. The biggest piece can be worn long, as a choker, or as a head-dress circlet. I find it hangs best as a choker or circlet, and the length is adjustable with a lobster clasp. The choker pictures here are at its smallest girth. My wife and model has a very slender neck; on me it fits more snugly.
This set is available for sale here: [link]