Aquamarine is a blue or cyan variety of beryl.Aquamarine is an official birthstone for those born in March. Aquamarine is exceptionally hard and has an outstanding vitreous glass-like luster. It is most famous for its breathtaking sea-blue colors which can range from pale light blue to medium-dark blue.A dark and deeply saturated blue is the most desirable and valuable aquamarine color. The more saturated the color, the higher the value, although almost all aquamarine is typically a lighter blue tone.Aquamarines of the best quality are eye-clean, transparent gems. Some gems can carry inclusions of long, hollow rods, a trademark of the beryl family.