emerald

Highly valued as gemstones, emeralds are a grass-green variety of beryl. The capacity of emeralds to deflect light and to break white light into its component colors is not high, so cut stones display little brilliancy or fire (flashes of color). The color that gives this gem its value comes from the presence of small amounts of chromium. The most important production of fine-quality gem material is Colombia; emeralds are also mined in Russia, Australia, South Africa, and Zimbabwe. Synthetic emeralds are identical to natural crystals and may rival them in color and beauty.