Aquamarine

Color:   Pastel ice blue to greenish blue
   
Gem Family:   Aquamarine is a member of the beryl family. The most famous beryl is emerald.
   
Source:   Aquamarine is found in Brazil, Zambia, Mozambique, Madagascar, Nigeria, and other countries.
   
Clarity:   Because the color is generally light, aquamarine should have a good clarity.
   
Size Range:   Aquamarine is regularly available from 1 to 5 carats. Generally small sizes are pale: aqua needs size to develop bright color. Some aquamarines are as large as 200 carats!
   
Shapes Available:   Aquamarine is most often found in ovals, emerald cuts, and cushions. It is also available in trillions and square checkerboard cushion shapes.
   
Enhancement:   Aquamarine is sometimes heated at low temperature to remove yellow, since most consumers prefer a pure blue to a greenish blue.
   
Lore & History:   Aquamarine, the gem of the sea, derives its name from "sea water". The reference is obvious: aqua sparkles like the sea and its color is pale to medium blue, often with a slight hint of green. Legends say that it is the treasure of mermaids, with the power to keep sailors safe at sea. Aquamarine is said to be a particularly strong charm when immersed in water. Its legendary power to soothe differences and ensure a long and happy marriage makes it a good anniversary gift. Aquamarine is the birthstone for March and the gem of Neptune, the planet named after the god of the sea.
   
Toughness & Hardness:   Aquamarine has a hardness of 7.5 on the Mohs scale and it is quite durable.
   
Care & Cleaning:   Like all gemstones, aquamarine should be protected from hard impacts. Clean with mild dish soap: use a toothbrush to scrub behind the stone where dust can collect.
   
Special Characteristics:   Aquamarines are found almost exclusively in special gem deposits known as pegmatites. These form when large lakes of molten rock solidify slowly beneath the surface of the earth. The final portion to crystallize encourages the growth of large crystals in an environment rich in the elements that form gems. In rare cases aquamarine crystals of 1,000 carats or more can form in pegmatites. You can see jumbo gems like these in museum collections like the Smithsonian Institution and the American Museum of Natural History.