Sources: Madagascar, Brazil, Nigeria, Mozambique, India
Common treatments: heating
Aquamarine is probably one of the most famous gemstones. Most people love it for its blue color which reminds them of both the sea and sky. Aquamarine naturally varies from green to blue. Greenish stones are often heated, changing the oxidation state of the iron elements in the crystal to bring out more blue.
However, incredibly rich blue Aquamarine can also occur naturally. A recent find in Madagascar produces vivid-blue crystals that rival the more well-known, but scarce "Santa Maria" material.
It is possible to find Aquamarine in impressively large sizes including stones over 100 carats so it's perfect for collectors and lovers of sculptural objects d'art. The largest aquamarine Nomad's ever faceted was a spectacular marine blue weighing over 2,900 carats.