Lithium is the third element in the periodic table, containing three protons, hence Z = 3, which defines its place in Mendeleev's periodic table of elements. It is a very light alkaline metal element with a density of 0.53, which is half the density of pure water. Lithium is used in various forms: minerals, metals, carbonates, hydroxides, various chemical compounds. A minimum of 120 lithium-bearing mineral species are identified in the database of the International Mineralogical Association. This number is a minimum, as many mineral species containing low amounts of lithium are not recorded. At the Earth's surface, several processes have an effect on the mobilization or immobilization of lithium, particularly processes of alteration, erosion and evaporation in the presence of variable amounts of water. By comparison, alkaline metals with larger ionic radius, such as rubidium and cesium, form octahedral complexes with water.