Important Colombian Emerald Ring. Photo courtesy M. S. Rau Antiques.

An outstanding, 9.28-carat Colombian emerald exhibits perfect color in this captivating ring. Displaying an intense, "Old Mine" green hue and incredible clarity, this octagonal step-cut gem is flanked by two shield-cut white diamonds weighing approximately 1.82 total carats. Certified by the GIA and C. Dunaigre Consulting as Colombian and untreated, this wonderful emerald and its supporting diamonds are set in platinum and 18K yellow gold. Price: $495,000

Emeralds have been among the most treasured gems in the world for over four millenia. In fact, they are so prized that, carat for carat, a fine emerald may be two to three times as valuable as a diamond. For centuries, Colombia has been the prime location for the mining of the finest quality emeralds in the world. Unlike emeralds found in other parts of the world, Colombian emeralds possess an incomparable brilliant green hue, free from any bluish influence, and a transparency that is simply unmatched by emeralds from other regions.

M. S. Rau Antiques. http://www.rauantiques.com/