Aquamarine

Aquamarine is a pale-blue to light-green variety of beryl.[2] The color of aquamarine can be changed by heat.[3]  The aquamarine has a chemical composition of Be3Al2Si6O18,[4] also containing Fe2+.[5] It has a hardness of 7.5 to 8.[6] Aquamarine contains no or few noticeable inclusions.[7] But it can have inclusions like mica, hematite, or salt-water.