Ga3PO7 crystal with size 18 x 15 x 12 mm(3) and good optical quality has been grown by the top-seeded Solution growth (TSSG) slow-cooling method from a Li2O-3MoO(3) flux system. The Vickers microhardness and optical properties of the as-grown Ga3PO7 crystal have been carefully studied. The results show that the Ga3PO7 crystal belongs to the harder materials, and Meyer's index numbers for (1 1 0) and (0 0 1) planes were about 1.45 and 1.60, respectively. The Ga3PO7 Crystal has a wide transmission range from 215 to 4300 nm. The smaller difference between the refractive indices values of n(o) and n(e) indicated that the Ga3PO7 crystal is an optically uniaxial negative crystal. (C) 2008 Published by Elsevier B.V.