Antique 18K Yellow Gold and Carnelian Intaglio Ring.  Large, oval intaglio measures almost 1 1/4" X 7/8".  Image of Roman emperor or statesman is carved from natural carnelian.  Subject wears an unusual metal coronet as opposed to the ubiquitous laurel wreath.  Twisted gold wire embellishes the edge of bezel No hallmarks visible.  Circa mid 19th century.