Characterisation of Ni silicate-bearing minerals by UV–vis–NIR spectroscopy: Effect of Ni substitution in hydrous Ni–Mg silicates

Three Ni silicate-bearing pimelite, nepouite and pecoraite minerals, from Australia have been investigated by UV–vis–NIR spectroscopy to study the effect of Ni–Mg substitution. The observation of three major absorption bands at 9205–9095, 15,600–15,190 and 26,550–25,660 cm−1 are the characteristic features of Ni2+ in sixfold coordination. The effect of cation substitution like Mg2+ for Ni2+ on band shifts in electronic and vibrational spectra enable the distinction between the Ni-bearing silicates.