Spectrum Vis-NIR reflectance spectrum of a pellet of kaolinite Spectrum Vis-NIR reflectance spectrum of a pellet of 1% Na-montmorillonite and 99% kaolinite Spectrum Vis-NIR reflectance spectrum of a pellet of 5% Na-montmorillonite and 95% kaolinite Spectrum Vis-NIR reflectance spectrum of a pellet of 10% Na-montmorillonite and 90% kaolinite Spectrum Vis-NIR reflectance spectrum of a pellet of 20% Na-montmorillonite and 80% kaolinite Spectrum Vis-NIR reflectance spectrum of a pellet of 40% Na-montmorillonite and 60% kaolinite Spectrum Vis-NIR reflectance spectrum of a pellet of 60% Na-montmorillonite and 40% kaolinite Spectrum Vis-NIR reflectance spectrum of a pellet of 80% Na-montmorillonite and 20% kaolinite Spectrum Vis-NIR reflectance spectrum of a pellet of 90% Na-montmorillonite and 10% kaolinite Spectrum Vis-NIR reflectance spectrum of a pellet of 95% Na-montmorillonite and 5% kaolinite Spectrum Vis-NIR reflectance spectrum of a pellet of 99% Na-montmorillonite and 1% kaolinite Spectrum Vis-NIR reflectance spectrum of a pellet of Na-montmorillonite