Magnesium (see dolomite) is used in cement, rubber, paper, insulation, chemicals and fertilizers, animal feed, and pharmaceuticals. Magnesium is obtained from the ore minerals Olivine (Fe,Mg) 2 SiO 4, Magnesite MgCO3, and Dolomite CaMg(CO 3) 2. Manganese Manganese is essential to iron and steel production.Web