Based on established crystallographic classifications and related examples found in nature, the concave and multidomain appearance of our crystals would indicate a twinned and polycrystalline system. In contrast with these expectations, we found that single crystals are formed. This claim is based on the analyses of the diffraction patterns of the entire crystals (n=5), including: (i) the shape and intensity distribution of the diffractions, (ii) Flack parameters, and (iii) symmetry analysis (Laue statistics). These analyses were conducted using a single crystal X-ray diffractometer with a relatively large crosssection beam, 100 μm, which ensured that all sectors of the stellate crystal are exposed throughout the diffraction experiment. Of note, X-ray diffraction data from twinned crystals display well-established pathologies that can be used to identify twinning. Our diffraction data (Ewald's sphere) show distinct spots and single defined patterns, fully compatible with a single-domain orientation (Figures and). The crystal structures were solved and fully refined to a high degree of resolution without any difficulty relating to twinning or multiplicity (Table ). The Flack parameters for all the analyzed crystals were close to zero, therefore excluding also the possibility of racemic twinning. The two types of crystals formed from the different copper salts are hexagonal, with the rare space group P622.