We have collected reflectance spectra of various unprocessed rock samples in the 450-1,650 nm wavelength range with a spatial resolution of 60 and 120 microm (diameter) and using three illumination modes. Spectra taken in diffuse reflectance (dark field) mode are comparable to those obtained from macroscopic measurements and can provide the basis for mineral detection at that spatial scale. The spectral discrimination of the dark field mode is demonstrated to be consistent with the spatial resolution of the microscope for the samples examined. These results support the conclusion that reflectance microspectroscopy in the visible and near-infrared regions can be a valuable tool for understanding mineral formation at the spatial scale of tens of micrometers.