A sintering composition and calcined object which are precursors for a sintered zirconia. The burned surface of the sintered zirconia gives an X-ray diffraction pattern in which the ratio of the height of the peak present around the location where a [200] peak assigned to the cubic system is to appear to the height of the peak present around the location where a [200] peak assigned to the tetragonal system is to appear is 0.4 or more, and a region located at a depth of 100 μm or more from the burned surface gives an X-ray diffraction pattern in which the ratio of the height of the peak present around the location where a [200] peak assigned to the cubic system is to appear to the height of the peak present around the location where a [200] peak assigned to the tetragonal system is to appear is 0.3 or less.