Vintage Colombian emerald coronet cluster ring. Set centrally with a cushion shape old cut natural Colombian emerald with no colour enhancement in an open back claw setting with an approximate weight of 2.30 carats, bordered by ten cushion shape old mine diamonds in open back grain and claw settings with a combined approximate weight of 2.71 carats, to an impressive coronet cluster design with a finely pierced gallery, fancy shape backholing, the slightly trumpeting shoulders leading smoothly through to a D-shape shank. Marked platinum with yellow gold settings, circa 1950, accompanied by Gemmological Certification Services report #79179-43.