Aquamarine (from Latin: aqua marina "water of the sea") is a blue or turquoise variety of beryl.
The pale blue colour is attributed to the presence of Fe2+ ions. Fe3+ ions produce a golden-yellow colour and when both ions are present, the colour is a darker blue.
The largest aquamarine gemstone ever mined was found in Marambaia, Minas Gerais, Brazil in 1910. It weighed over 110kg and its dimensions were 48.5cm long by 42cm in diameter. The largest cut aquamarine is the Dom Pedro, now housed in the Smithsonian Institution's National Museum of Natural History.