We synthesized the MOFs (CSTAR-NO3 and CSTAR-SO4) using only the building blocks constituting the crystals, namely, a metal salt and an organic ligand (AdDB). Often additives are used to influence and control the size and shape of MOF crystals ; however, in our case no additives were used to control the growth and the shape of the facets (Scheme 1A). The crystals were grown in a sonicated solvent mixture (DMF/CHCl3 3:1 v/v) via the solvothermal reaction of a copper salt (Cu(NO3)2 or CuSO4) with AdDB in a molar ratio of 2:1, according to our reported procedures, at 105 o C for two days. Optical and scanning electron microscopy (SEM) show the formation of unusually shaped "stellate" prism (Figures and). Regardless of the counterion of the metal salt (NO3 -, SO4 -), the crystals have a similar, uniform morphology. Their concave polygon shape resembles a six-pointed star. These stars have a multidomain appearance consisting of a central hexagon surrounded by six-connected pentagons. Lateral views show that both the central hexagon and the pentagons are protruding. The diameters of the CSTAR-NO3 and CSTAR-SO4 crystals, measured as the distance between two opposite points, is 32±6 µm and 177±41 µm, respectively. The angles, defined by adjacent points, and center of the CSTAR-NO3 and CSTAR-SO4 crystals are 60°±1° and 60°±2°, respectively. Their twelve lateral facets are of a uniform length (9.4±2.3 µm and 48.4±8.6 µm for CSTAR-NO3 and CSTAR-SO4, respectively). The morphology allows one to relate the crystal facets by symmetry elements of the 6/mmm point group, i.e., a six-fold symmetry perpendicular to the stellate base, mirror planes parallel to the stellate bases and passing through the base vertexes (Scheme 1B).