For the solutions with ≤ 0.01 mol•kg -1 CoF2, the spectra of path 1 samples are almost same as those of path 2 albeit with slight intensity difference in absorption band of 360-700 nm. For the solutions with ≥ 0.05 mol•kg -1 CoF2, the spectral difference aforementioned between paths 1 and 2 samples develops and the spectra exhibit new difference in the range of 220-340 nm, where both absorption shoulders are observed in the solutions prepared by path 1 while they are not observed in the path 2 samples (Fig. ). These spectral differences are also observed between a series of CoF2 and CoSO4 aqueous solutions with identical concentration. It is found that the spectral features of Co 2+ //F -//Na + //SO4 2-solutions prepared by path 1 are very close to those of diluting the subsaturated CoF2 solutions with identical concentration, while those prepared by path 2 are very close to those of CoSO4 solutions, indicating that both prepared paths samples are different states, although they have identical component.