Aquamarine is a beautiful blue-green gemstone, a variety of the mineral beryl, named from Latin for "seawater," known for its calming, sea-like colors and used in jewelry, symbolizing tranquility, clarity, and love, often heat-treated to enhance its desirable deep blue hue. It forms hexagonal crystals, ranks 7.5-8 on the Mohs hardness scale, and is associated with the March birthstone and the throat chakra, believed to calm nerves and aid communication.