Aquamarine is a pale-blue to light-green variety of beryl. The color of aquamarine can be changed by heat (though this practice is frowned upon by collectors).

Aquamarine has a chemical composition of Be3Al2Si6O18,= also containing Fe2+. It has a hardness of 7.5–8 on the Mohs scale. While aquamarine often contains no inclusions, it can have them, noticeable or not, composed of content such as mica, hematite, or saltwater.