A new nonlinear optical material GdxLa1-xSc3(BO3)(4) (GLSB) has been synthesized in the trigonal huntite-type structure. The composition parameter x, which defines the existence region of the trigonal huntite-type structure, was determined. Large single crystals were successfully grown by a high-temperature top-seeded solution growth method using Li6B4O9-LiF as a flux. Evidenced by single-crystal X-ray diffraction measurements, the member Gd0.22La0.78Sc3(BO3)(4) crystallized in space group R32 with cell dimensions a=9.7933 and c=7.9540 angstrom. The UV absorption edge for polished pieces exhibited at a wavelength shorter than 200 nm. Sellmeier equations were established on the basis of the refractive indices measured by the auto-collimation method. The nonlinear optical coefficient d(11) was determined to be 2.08 pm/V by the modeling and optical measurements of powders. (C) 2011 Elsevier B.V. All rights reserved.