Example of increasing absorbance with larger water content for mixtures of Goethite and basalt (each component dry sieved to diameters less than 300 microns). Reflectance spectra are converted to absorbance using Kubelka-Munk. Vertical axis is offset to align curves. Water content varies from 2% (lowest curve) to 8% (highest peak); intermediate curves represent 4% and 6% water.