Analysis of materials’ stability based on the crystallographic structure by the enforced external impulsion of dynamic shock waves is now considered one of the most currently required investigations from the perspective of academic and technological sciences. While performing shock wave experiments on single- and polycrystalline materials, the results obtained are abrupt, so there is no a clear understanding of the changes occurring. In this context, the authors have demonstrated the crystallographic structural stability of polycrystal nickel sulfate-hexahydrate (NSH) [NiSO₄.6H₂O] under dynamic shock wave-exposed conditions, comparing the results to the previously reported single-crystal NiSO₄.6H₂O. The shock wave impact on the titled polycrystalline samples has been assessed by Raman spectroscopy, X-ray diffraction, electronic spectral and magnetic properties. Based on the observed results, the test samples do not undergo any crystallographic structural transitions even at 100 shock pulses-loaded conditions, whereas the single crystal NiSO₄.6H₂O undergoes continuous phase transitions between the crystalline and amorphous states against the shock pulses of counts 1 to 8. Based on the systematic investigations of the obtained results, it is authenticated that the polycrystalline samples have higher structural stability than the single crystalline samples of NiSO₄.6H₂O.