Pure and neodymium-doped gadolinium calcium oxoborate crystals of high qual
ity were grown by the Czochralski method. The orientation of crystal was pr
ecisely determined, and the samples for measurements were prepared. Through
synchrotron x-ray topography and high-resolution x-ray diffractometry, the
twin structure was discovered. Some properties such as the figure of merit
value, and dielectric, piezoelectric, and elastic constants were measured
along with a discussion of the anisotropy of the laser properties.