The mineralogical and VNIR spectroscopic characteristics of different stages of kaolinized nontronite

This database includes mineralogical and VNIR spectroscopic characteristics of different stages of kaolinized nontronite. A series of kaolinized nontronite samples were prepared by converting nontronite to kaolinite with different experimental durations. XRD analysis was performed on a Rigaku MiniFlex-600 X-ray diffractometer with Cu/Kα radiation and a Ni filter operating at a current of 15 mA and voltage of 40 kV. SEM images were obtained using an Analytical Scanning Electron Microscope (TESCAN MIRA 3) equipped with an energy dispersive X-ray spectrometer (EDS) operated at an accelerating voltage of 20 kV and working distance (WD) of 15-16 mm. TG analyses were conducted on a Netzsch STA 409PC instrument. VNIR reflectance spectroscopy spectra were acquired at wavelengths from 350–2500 nm using an Analytical Spectral Devices (ASD) Terraspec-4 spectrometer.