Aquamarine is a member of the Beryl family. Other beryls are Emerald and Morganite. Aquamarines light blue color is more pure and its attributes less brittle than Emerald, making it a desirable gem for special occasion wear.
Like most colored gemstones aquamarines are graded on a letter scale.
B Light color; included; good cut
A Medium to light color; slightly included; good cut
AA Medium color; eye clean; good cut
AAA Medium to dark color; eye clean; good cut
Most aquamarines have been heated to improve their color and sometimes also clarity. Heating is a permanent enhancement, as lasting as the gemstone itself. Heated aquamarines can be re-cut and re-polished if needed without affecting it's color hue.