Occurrence of group 2 metals

Beryllium occurs principally as the silicate mineral beryl, Be₃Al₂[Si₆O₁₈] it is also found in many natural minerals, and precious forms include emerald and aquamarine. Magnesium and calcium are the eighth and fifth most abundant elements, respectively, in the Earth’s crust, and Mg, the third most abundant in the sea. The elements Mg, Ca, Sr and Ba are widely distributed in minerals and as dissolved salts in seawater; some important minerals are dolomite (CaCO₃.MgCO₃), magnesite (MgCO₃), olivine ((Mg,Fe)₂SiO₄), carnallite (KCl.MgCl₂.6H₂O), CaCO₃ (in the forms of chalk, limestone and marble), gypsum (CaSO₄.2H₂O), celestite (SrSO₄), strontianite (SrCO₃) and barytes (BaSO₄). The natural abundances of Be, Sr and Ba are far less than those of Mg and Ca (Figure 1.1).