Spectral emissivities are give for Y2O3, Sm2O3, Gd2O3, Er2O3 and Lu2O3 in the visible portion of the spectrum for temperatures up to 1600 deg C. The data were obtained using a carbon arc image furnace as an energy source, a photovoltaic cell as a radiation detector, a thermocouple as a temperature detector, and a magnesium oxide smoked plate as a standard of reflectance. Emissivity is calculated from a curve of combined reflectance and emitted radiation versus temperature by using Kirchoff's law and a method of successive approximations to solve Wien's equation.