Tags: Chemical Substance, Mineral.
Emerald is a gemstone and a variety of the mineral beryl (Be3Al2(SiO3)6) colored green by trace amounts of chromium and sometimes vanadium. Beryl has a hardness of 7.5–8 on the 10-point Mohs scale of mineral hardness. Most emeralds are highly included so their toughness (resistance to breakage) is classified as generally poor.
