Beryllium was discovered by Louis-Nicolas Vauquelin in 1798. Friedrich Wöhler (1800 - 1882) and A. A. Bussy independently isolated the metal in 1828 by reacting potassium with beryllium chloride. It is one the lightest known materials and is the least reactive of the Group 2 elements. It is unreactive with water and air unless heated to a high temperature. It has two valence electrons and can form two covalent bonds. There are four available atomic orbitals in the valence shell of beryllium. This availability dictates the formation of polymeric compounds with beryllium.
It is found in the mineral beryl Be3Al2(SiO3)6. Aquamarine and emerald are precious froms of beryl.