Pale greenish blue or bluish green variety of beryl that is valued as a gemstone.
The most common variety of gem beryl, it occurs in pegmatite s, in which it forms much larger and clearer crystals than emerald , the dark green variety of beryl. Aquamarine occurs in Brazil, which is the chief source, and in such other sites as the Ural Mountains, Madagascar, Sri Lanka, India, and Maine, New Hampshire, Connecticut, North Carolina, and Colorado in the U.S. Heat treatment is commonly used to improve the colour of gem beryls.