FIELD: inorganic crystals technology. SUBSTANCE: invention, in particular, relates to magnesium-based hydroxides and oxides, which are prepared by hydration of solid solutions of metal oxides with general formula Mg1-zM2+zO, wherein M2+ is ion of at least one divalent metal selected from group including Mn2+, Fe2+, Co2+, Ni2+, Cu2+, Zn2+ and z ranges from 0.01 to less than 0.5, with average particle size of primary crystal ranging from 2 to 10 in presence of monocarboxylic and/or hydroxymonocarboxylic acid in aqueous medium. Reaction results in formation of solid solution of metal hydroxide with high aspect ratio represented by general formula Mg1-xM2+x(OH)2, in which x ranges from 0.01 to less than 0.5, preferably from 0.1 to less than 0.3. Crystal is in the form of hexagonal plate with average thickness from 0.01 to 0.5 mcm and average diameter 1-10 mcm, aspect ratio being at least 10. Solid solutions obtained show new properties such as enhancement effect to polymers, imparting plasticity to cosmetics and analogous products and are also capable of absorbing ultra-violet emission in addition to such common properties of magnesium-based solid solutions of hydroxides and oxides as capability of inhibiting burning, neutralizing acids, accepting acids in halogenated rubbers, and thickening fiber-reinforced plastics. EFFECT: widened useful application range. 6 cl, 6 ex
