Mexican fire opal  natural polished sterling silver artisan split shank large ring. Good used condition with little to no signs of normal wear. Split shank design. Stamped on the inside of the band 925 with an unidentified hallmark. Very large high set prong set tumbled opal. The colors dance inside the opalescent part of the stone. There is a small quartz pocket on the bottom edge of the stone. The edges have been left natural with a highly polished top. 

Acid tests positive for sterling silver. 

Ring measures size 10.