A sprinkling of clasts of gray and white with the freeform shape make this a fun piece.  The mounting is a pebbled texture, blackened silver. This is from a slice of NWA 13119 and is set in a hypoallergenic, tarnish resistant sterling silver with a pure silver bezel.  The pictured 20 inch heavy weight sterling silver rounded box chain, 1.8mm, is included. I can make this chain in any length.