Aquamarine

Aquamarine is a type of Beryl which is the name given to a family of six chemically related stones, including bixbyite, emerald, goshenite, heliodor, and morganite. All beryl’s are considered precious stone and are composed of Be₃Al₂(Si₆O₁₈). They form according to a hexagonal crystal structure, and have a hardness of 7.5-8 on the Mohs scale.