Effect pigments

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An effect pigment based on Al2O3 flakes, which are coated with at least one metal oxide or mixed metal oxide layer(s), preferably 1 or 2 surface layers, wherein the amount of Al2O3 of the flakes and the amount of metal oxide(s) of the coating layer(s) is 27 : 73 to 83 : 17 based on the total effect pigment. The Al2O3 flakes can be doped with, 0.01-5 wt% of TiO2, ZrO2, SiO2, SnO2, In2O3, ZnO or combinations thereof, but preferably TiO2 in the rutile or anatase modification or ZnO. The particle thickness of the Al2O3 flakes can be 130-500 nm and have a standard deviation of thickness distribution of < 80. The effect pigment can also contain a 0.5-10 nm thick surface protective layer which may contain 0.2-2 wt% of at least one rare earth metal oxide, preferably cerium oxide, 0.4-6 wt% of at least one metal oxide selected from silicium, aluminium or zirconium or mixtures thereof and 1-10 wt% of an organic compound which can be a coupling agent, organofunctional silanes, amino compounds or organic phosphorus compounds. The pigment can be used in an amount of 0.01-95 wt% in formulations e.g. paints or coatings.