 All three stable elements occur in heavy mineral sands ore deposits , which are placer deposits formed , most usually in beach environments , by concentration due to the specific gravity of the mineral grains of erosion material from mafic and ultramafic rock . The titanium minerals are mostly anatase and rutile , and zirconium occurs in the mineral zircon . Because of the chemical similarity , up to 5 % of the zirconium in zircon is replaced by hafnium . The largest producers of the group 4 elements are Australia , South Africa and Canada . 
