Aquamarine is the sea-blue variety of beryl, the same mineral family as emerald. Its name comes from the Latin for seawater, and the colour, caused by traces of iron, runs from pale sky blue to a rich blue-green. Roman sailors carried it for safe voyages, and today it is the birthstone for March. Most fine aquamarine comes from Brazil, with lovely material also mined in Nigeria, Mozambique, Madagascar and Pakistan. It often grows in large, clean crystals, so big, eye-clean stones are more affordable than you might expect.
With a hardness of 7.5 to 8, aquamarine is a genuinely practical gem for rings, bracelets and everyday wear. Most stones on the market are gently heated to soften any greenish tint into a purer blue. That is a stable, standard trade practice and nothing to worry about. It is usually faceted to make the most of its clarity. Warm, soapy water keeps it sparkling, and it is best kept away from prolonged heat. Blue glass and synthetic spinel are common imitations, so buy from a seller who guarantees natural stones, as we do.
Emerald and morganite are also beryls, while blue topaz is its most common look-alike.
