The results of a crystal structure refinement of an anisotropic grandite garnet specimen with composition Gro 36.4 And 63.6 are given. The structure obtained has orthorrombic symmetry (space group Fddd) and is compared with similar results obtained by other authors. In all cases the reduction of symmetry is due o the ordering of Fe3+ and Al in octahedral sites. Non cubic structures of grandites are discussed in connection with optical, morphological an grouwth features of these minerals.
