Ternary Hg1-xCdxI2 (0 < x < 60) crystals were directionally solidified under similar to 20 atm of argon pressure. For 0 < x < 0.17, the crystals have the same red color as pure alpha-HgI2. For x > 0.17 the crystals are yellow. In the full compositional range 0 < x < 60, the lattice is tetragonal, as in pure alpha-HgI2. The yellow crystals have a higher crystalline perfection and degrade less than the red crystals during sample preparation by cleaving and thus may be more suitable for fabrication required for X- and gamma-ray detectors. (c) 2006 Elsevier B.V. All rights reserved.