KLu(WO4)(2) (KLuW) crystals with sizes up to 42 x 32 x 12 mm(3) have been grown from the K2W2O7 solvent system by the top-seeded solution growth (TSSG) slow-cooling method. The crystal structure of monoclinic KLuW crystals has been refined in space group C2/c at room temperature by using single-crystal X-ray diffraction data and the KLuW morphology was studied from the Hartman-Perdok theory. Crystal shapes vary greatly with the seed orientations, whereas {110}, {111}, {020} and {301} faces are more developed than the others. (c) 2006 Elsevier B.V. All rights reserved.