Gachala Emerald

The Gachala Emerald is an 858 carat uncut emerald crystal, about 5 centimeters across, regarded as one of the largest and finest gem quality emerald crystals in the world. It is part of the permanent collection of the Smithsonian Institution's National Museum of Natural History in Washington, D.C., where it carries catalog number 122078.

The crystal was found in 1967 at the Vega de San Juan mine in Gachala, a municipality in the Cundinamarca Department of Colombia, and was named for the town where it was discovered. Colombia produces most of the world's fine emeralds, and the Gachala crystal shows the vivid green color for which Colombian stones are known. Crystals of this size and quality are rarely preserved intact, since most large rough emeralds are cut into gems.

Soon after its discovery the emerald was acquired by the New York jeweler Harry Winston, who donated it to the Smithsonian in 1969. The gift was one of several by Winston that helped build the museum's National Gem Collection into the largest of its kind. Because it was never faceted, the Gachala Emerald is displayed as a natural crystal rather than a finished jewel.