Spectrum Vis-NIR spectrum of NH4-Montmorillonite with 0-25µm grain sizes at 180K Spectrum Vis-NIR spectrum of NH4-Montmorillonite with 0-25µm grain sizes at 190K Spectrum Vis-NIR spectrum of NH4-Montmorillonite with 0-25µm grain sizes at 200K Spectrum Vis-NIR spectrum of NH4-Montmorillonite with 0-25µm grain sizes at 210K Spectrum Vis-NIR spectrum of NH4-Montmorillonite with 0-25µm grain sizes at 220K Spectrum Vis-NIR spectrum of NH4-Montmorillonite with 0-25µm grain sizes at 230K Spectrum Vis-NIR spectrum of NH4-Montmorillonite with 0-25µm grain sizes at 240K Spectrum Vis-NIR spectrum of NH4-Montmorillonite with 0-25µm grain sizes at 250K Spectrum Vis-NIR spectrum of NH4-Montmorillonite with 0-25µm grain sizes at 260K Spectrum Vis-NIR spectrum of NH4-Montmorillonite with 0-25µm grain sizes at 290K