Digital near-infrared (NIR) cathodoluminescence (CL) imaging and image processing

Abstract

Infrared luminescence is recognized in many minerals; however, few reported examples of infrared cathodoluminescence (CL) imaging are cited in the literature. Low-light digital web cameras can be modified by removing their infrared blocking filters to allow the imaging of minerals and rocks in the near-infrared (NIR). Preliminary investigation of a limited number of minerals has shown that many display cathodoluminesce in the NIR. Of the minerals found to have NIR-CL, the feldspars are notable as they commonly reveal hidden details of growth and alteration not easily observed with polarized light microscopy (PLM) or normal visible CL.