This peacock ore pendant is handcrafted from 14K/20 gold filled wire, and a natural nugget of bornite. This one has a lot of purple, blue, and copper colors. Bornite, or Peacock Ore, is a copper ore. The chunks in these pendants are completely natural. The iridescent colors are basically tarnish composed of copper oxides and hydroxides. The tarnish layer is very thin and light bouncing between the surface of the stone and the layer of tarnish creates the colors, much like the effect that oil creates on water. Bornite tends to have purple and blue colors of tarnish, but it is often intergrown with chalcopyrite, which also tarnishes and adds greens and yellows. There are a lot of metaphysical properties associated with peacock ore, but an obvious one is that it brings joy and happiness. I love these rough, chunky pendants on big nubby sweaters in the wintertime. The texture of the stone against the texture of the sweater really works. While they look heavy, on a large chain over a bulky sweater you don’t feel them. DO NOT PUT BORNITE in an ionic cleaner. The colors will change faster than you can rescue it! I think it is the metals in the stone. You’ll get a very lovely color that will improve with age - but it won’t be purple and blue any more. 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 pretty rocks 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 1 5/8" x 2 7/8" 42mm x 73mm 4.5mm bail