American Art Deco ring (likely by Louis C. Tiffany for Tiffany & Co.) set with a large blue zircon (approx. 64 carats by calculation, 20mm x 20mm x 19mm) set in a fancy platinum mount further set with 14 round cut diamonds, four bullet shaped gold/orange citrines and two kite shaped gold/orange citrines, marked: very deeply stamped letters as a maker’s mark on the inside of the shank, c. 1930