This huge emerald — a 167.97 carat, oval cabochon cut — is the centerpiece of the Mackay Emerald Necklace given to Mrs. Anna Case Mackay — a New York Metropolitan Opera prima donna — as a wedding gift  by her husband Clarence H. Mackay in 1931 and later donated by her to Smithsonian’s National Museum of Natural History.

It is set in an art deco diamond and platinum pendant designed by Cartier. Its value is estimated at around $7 million.

The Mackay Emerald is a 167.97-carat, oval cabochon-cut, deep grass-green colored emerald, with its horizontal and vertical diameters approximately 2 inches (5 cm). The stone is translucent (light being transmitted through the stone, but its interior not being visible), as the stone is heavily included. The presence of inclusions in emeralds is a common feature, and characteristic of all natural emeralds.

We think this demonstrates admirably that the presence of inclusions in emeralds is not necessarily a bad thing!

Mackay emerald and diamond necklace
Mackay emerald closeup showing heavy inclusions