Cathodoluminescence (CL), light generated by irradiation of material with fast electrons, is used to characterize optical properties on the nanoscale. The CL emission from a rock gives insights into crystal growth, zonation, cementation, replacement, deformation, provenance, trace elements, and defect structures. This can be used to fingerprint rocks and reveal interesting spatial textures on a submicron scale.

The SPARC is an integrated CL system with a high collection efficiency for unparalleled sensitivity. The SPARC is capable of multiple imaging modes, including hyperspectral imaging and spectroscopy.