Aquamarine is a type of beryl with a hexagonal crystal structure and a chemical formula of Be3Al2Si6O18, a beryllium aluminum silicate mineral.
Attractive aquamarine stones are also produced by Zambia, Madagascar, Malawi, Tanzania, and Kenya.
Aquamarine is also the name for a color, which is a shade between green and blue.
Clear yellow beryl, such as occurs in Brazil, is sometimes called aquamarine chrysolite.
Aquamarine, typically, is on the low end of the specific gravity range, normally at less than 2.7.
When corundum presents the bluish tint of typical aquamarine, it is often called "oriental aquamarine."
The biggest aquamarine ever mined was found at the city of Marambaia, Minas Gerais, Brazil, in 1910.
Much of today's aquamarine is heated to give it a better color blue.