Hinged Sterling Silver Pendant with Agate (vs: Ocean Jasper) and Obsidian

I was told the stone I used in this pendant was ocean jasper, but as it has translucent bands with drusy inclusions, it looks more like agate to me. Whatever, it is an unusually attractive material in white, grey and black with flecks of green and gold.  The larger cabochon is bezel set and embellished with twisted silver wire, as is the contrasting obsidian cabochon.  The two portions of the pendant are connected by a silver hinge constructed from sterling silver tubing. The pendant is 3" long from the top of the bale, and is 1 1/8" wide. It is shown on a 20" sterling chain which is included.