A Nd-doped GdNbO₄ single crystals have been grown successfully using the Czochralski technique. The chemical etching method was employed to study the defects in the structural morphology of Nd:GdNbO₄ crystal with phosphoric acid etchant. Mechanical properties (such as hardness, yield strength, fracture toughness, and brittle index) of the as-grown crystal were systematically estimated on the basis of the Vickers hardness test for the first time. The transmission spectrum of Nd: GdNbO₄ was measured in the wavelength range of 320-2400 nm at room temperature, and the absorption peaks were assigned. Results hold great significance for further research on Nd:GdNbO₄.