The round clasts with the rectangular pendant shape give a great balance and visual contrast.  I pebbled and blackened the front of the mounting.  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.