The California Institute of Technology created this website to provide valuable information about the color in minerals and data on mineral absorption spectra and Raman spectra. The modest site features additional information on silica polymorphs, desert varnish, ametrine, and manganese dendrite. Students can discover the technology used to collect the spectra data including the diode-array spectrometer. Researchers can find an updated, lengthy list of references of papers dealing with mineral optical spectroscopy.