An emerald is a precious gemstone prized for its rich green color. True emeralds get their distinctive green from traces of chromium and sometimes vanadium trapped in the crystal structure as it forms deep underground. The finest emeralds glow with an intense green that seems almost alive, though most emeralds contain tiny internal fractures and inclusions that gemologists call their “garden.”

Emeralds belong to the beryl family of minerals, making them cousins to aquamarine. They form over millions of years under specific conditions of heat and pressure. Colombia produces many of the world's finest emeralds, though they're also found in Zambia, Brazil, and other locations.

The word emerald also describes that particular vivid green color. Writers might describe a forest as emerald green or an emerald lawn. In The Wizard of Oz, Dorothy and her friends journey to the Emerald City, where everything gleams with green brilliance.

Because genuine emeralds are rare and valuable, people have treasured them for thousands of years. Cleopatra loved emeralds so much that she claimed ownership of all the emerald mines in Egypt. Today, a high-quality emerald can be worth more per carat than a diamond.