CRYSTAL CHEMISTRY, CLASSIFICATION POSITION AND NOMENCLATURE OF LAYERED DOUBLE HYDROXYDES

The layered double hydroxides (LDH), also known as hydrotalcite–like minerals, have very versatile properties and find a very wide application in practice [1]. They are known as minerals since 1842, when Hohsteter has discovered hydrotalcite but even nowadays new minerals of this group are still discovered (see table 1). The crystal structures of these minerals and some of their useful properties have been studied using natural varieties. [2,3]. Crystal chemical characteristics The layered double hydroxides have the following common chemical formula