Twinning of ZrO2:Sc2O3 (10 mol%) fluorite-type crystal was investigated by the Laue method. A chevron-like configuration of ferroelastic domain structure was observed in rhombohedral phase of the studied crystal. It was formed by crossing of W-type (1 0 0), (0 0 1) and (1 0 1) domain walls and demonstrates the nonreversibility of this domain wall configuration at thermal heating from ferroelastic phase to paraelastic cubic phase and following cooling to ferroelastic rhombohedral phase.