Near-Infrared Spectroscopy Study of OH Stretching Modes in Pyrophyllite and Talc

Pyrophyllite and talc are both tetrahedra–octahedra–tetrahedra (TOT)-type phyllosilicates, but differences can be found in the stacking mode of layers ion occupation. Fourier transform infrared spectroscopy was used to differentiate between pyrophyllite talc. In 400–600 cm?1 region, exhibits six peaks, while only five peaks. 1000–1200 three clear peaks at approximately 1051, 1070, 1121 cm?1; one strong peak near 1020 cm?1. The near–infrared (NIR) region 4000–4700 an intense around 4615 cm?1, which is attributed combination OH Si-O-Si stretching bands. Talc has a maximum located 4324 vibration. addition, secondary 4366 two other weaker 4054 4180 7000–7250 first fundamental overtone group vibrations. common characteristic band these minerals 7175–7183 vibrations also generated by adjacent overtones. 7094 appear 3630 (±5) 3642 (±3) cm?1.The factor vibration 1.95 (±0.003). Therefore, mid-infrared (MIR) NIR regions distinguish talc, providing research basis for further exploration related geological areas.