Pure, Mg2+ and Zn2+ doped BTCC single crystals are grown from their aqueous solutions at 301 K. The grown crystals are characterized by single crystal XRD, FTIR and UV-Vis-NIR spectral studies. The preliminary investigations of the UV-Vis-NIR spectra on the doped samples suggest an increased percentage of transmission in comparison to pure BTCC crystals. The SHG efficiency of the metal doped BTCC crystals is found better than the pure ones. It is estimated from the microhardness, studies that the mechanical strength of the BTCC crystals are improved due to the metallic (Mg2+ and Zn2+) substitutions. (C) 2004 Elsevier B.V. All rights reserved.