Orientational Degeneracy of Defects in Diamond
Some manifestations of optical anisotropy in diamond crystals with defects are due to reduction of the symmetry group of the growth pyramid caused by the removal of the orientation degeneracy of defects during tangential growth. In this case, the point symmetry group of the growth pyramid is determined not only by the symmetry group of the growth face, but also by the symmetry of the defects themselves.