The Maximilian emerald ring (G5024). Photo by Chip Clark.

This 21.04-carat Colombian emerald was once set in a ring worn by Mexico’s ill-fated emperor, Ferdinand Maximilian Joseph.  An Austrian archduke crowned emperor of Mexico in 1864, he was executed during an uprising only three years later.  The emerald in its present platinum ring setting, designed by Cartier, Inc., is enhanced by six baguette cut diamonds. It has the rich deep grass-green color of fine emeralds from Colombia as well as fine clarity and transparency.  Mrs. Marjorie Merriweather Post donated the Maximilian Emerald Ring to the Smithsonian in 1964.  Marjorie Merriweather Post was heiress to the Post cereal fortune and a collector of French and Russian art.  This ring is one of several major donations she generously gifted to the National Gem Collection; others include the Blue Heart Diamond, Napoleon Diamond Necklace, Marie-Louise Diadem, Post Emerald Necklace, and Marie Antoinette Earrings (through her daughter Eleanor Barzin).  Along with these amazing gifts, the Maximilian Emerald Ring is on display in the Gem Gallery at the National Museum of Natural History.