Author name: Jens Götze

Luminescence imaging and hyperspectral luminescence mapping are powerful analytical tools with widespread applications in geosciences and materials science. The luminescence of minerals is mainly a defect phenomenon caused by lattice defects and/or impurity elements. This in turn allows one to study trace-element composition and the structural state of a sample by means of its emission. One of the most spectacular and widely used applications of luminescence images is to visualise internal textures in minerals that are not revealed by other analytical techniques. Herein we present a selection of examples for the extraordinary sensitivity of luminescence imaging. We also show that precise information on samples is obtained if luminescence imaging is combined with spectroscopic analysis of the emission and/ or complementary analytical techniques.

Luminescence is the eye-catching phenomenon of light emission by a mineral after some input of energy (the excitation). Although commonly used in Earth sciences only to produce images, much more can be extracted from this phenomenon. Luminescence is extremely sensitive to low levels of emitters (activators), which helps to reveal the geochemistry or the creation of defects. We give an overview of the great variety of techniques (cathodoluminescence, photoluminescence, and more), discuss vocabulary issues (such as excitation versus stimulation, or the different types of persistent luminescence phenomena), and propose wording we feel best reflects today’s knowledge. We explain the basics of luminescence spectroscopy with emission, excitation, and time-resolved spectra to obtain useful data for Earth scientists.