Swank Goldtone Vintage Cufflinks Designer Signed Black Glass Stone Encased Setting

These cufflinks do show surface ware on the underside of them.  They are rectangle in shape with a black stone in the middle.  I dont know what the stone is ... could be hemitite or onyx (not sure) but it is cold to the touch so its not plastic.  

The setting has brushed texture in the area where the stone is but very textured all around the other sides.  

Measures 1 inch long x 1/2 inches tall.  The swivel bullet backing works like it should.  Each cufflink is marked with SWANK on the underside.