few inclusions makes it less susceptible to nicks or cracks than many other gems. With an "8" ranking on the Mohs hardness scale, the stone is very durable and can stand up to everyday wear. Its clear, pale brilliance makes it an appropriate stone for all types of jewelry - and it combines well with all jewelry metals and is flattering to most skin tones.

Aquamarine is commonly heat-treated to permanently remove green overtones. Unlike its sister stone the emerald, aquamarine generally isn't plagued by surface fractures - which means the stone isn't usually treated with fillers, resins or oils. Even so, avoid mechanical cleaners. To clean aquamarine, use warm soapy water.

The largest known aquamarine is a 243-pound stone found in Brazil in 1920. It was cut into many smaller stones and a 13-pound uncut piece resides

in the American Museum of Natural History. Another noted aquamarine is an 879.5-carat flawless, step-cut, sea green stone on display in the British Museum of Natural History.