Optical constants of particulate minerals from reflectance measurements: The case of calcite

In this work we describe a new method for the derivation of the optical constants of a particulate sample by means of the Hapke theory, starting from directional-hemispherical reflectance measurements. This approach has been applied to calcite fine grains, whose spectra have been obtained in our laboratory in the spectral range 0.3-2.3μm.