Aquamarine is a type of pale blue to green gemstone which has been used in ornamental jewelry for centuries. It is a type of beryl, a stone which contains a mixture of beryllium, aluminum, and silicate: other beryls include emeralds, golden beryls called heliodors, and morganites, also known as rose beryls. The chemical formula for aquamarine, along with all other beryls, is Be3Al2(SiO3)6. The color of the stone comes from trace amounts of iron which have become embedded in the hexagonal crystalline structure of the stone.
Aquamarine, along with beryls in general, has been recognized and valued as a gemstone for thousands of years, and even appears in the Bible. The double reference to water in the name, which is a compound of the Latin words aqua, for water, and marina, "of the sea" suggests that the ancients connected the stone closely with water. In addition to appearing in settings with other, more precious gems, aquamarine was also highly valued by sailors, who considered it to be a lucky stone.
According to sailing lore, aquamarine could ensure safe passage for sailors, and many wore the stone on their bodies or slept with an aquamarine under the pillow for peaceful sleep. Sailors also believed that mermaids had tails made of aquamarine. In addition to being the sailors' lucky stone, aquamarine is also the birth stone for March, and 19th anniversary wedding gifts traditionally include aquamarine in some cultures. In the Middle Ages, many people felt that the stone had health enhancing properties, and some carried it to protect themselves from poison.
The primary source of aquamarine is Brazil, although it is also found along the Eastern Seaboard of the United States. The stone has been found in Madagascar, Sri Lanka, India, and the Ural mountains as well. No standalone deposits of aquamarine have been found: the stone is associated with deposits of other rocks and ores such as tin, granite, feldspar, and tourmaline. The stone can be almost clear to rich blue in color, and it is sometimes heat treated to enhance the color. Because of the clear, sparkling appearance of aquamarine, it is usually presented in a faceted cut, so that the faces of the stone dance in the light.
Caring for aquamarine is relatively easy, because the stone is hard and difficult to crack. It can be washed with a mild soap and water solution, and even brushed with a toothbrush if it starts to collect dirt and grime. Be careful when choosing a detergent, as some detergents may react with the metal the stone is set in, and keep aquamarine out of the heat, as this may damage the stone. The stone should maintain a proper oil and moisture balance by being worn next to the skin, although avoid wearing aquamarine if you have an active day planned, as the stone can crack or chip if slammed against something.