(ca-thod-o-lum-in-es-cence) The emission of light by a mineral caused by electron bombardment (CL is a type of luminescence). Cathodoluminescence can be observed directly using microscope-mounted systems or it can be recorded indirectly using electron microbeam instumentation. Cathodoluminescence images of several minerals captured with a scanning electron microscope (SEM) are available at CL web.

The emission of light photons by a material under electron bombardment.

Cathodoluminescence is an optical and electrical phenomenon whereby a beam of electrons is generated by an electron gun (e.g. cathode ray tube) and then impacts on a luminescent material such as a phosphor, causing the material to emit visible light. The most common example is the screen of a television. In geology, mineralogy and materials science a scanning electron microscope with specialized optical detectors, or an optical cathodoluminescence microscope, is used to examine internal structures of semiconductors, rocks, ceramic, glass etc. in order to get information on the composition, growth and quality of the material.