The X-ray fluorescence (XRF) spectrometer is an analytical instrument that employs X-ray technology to perform routine and minimally invasive chemical analyses of various geological materials such as rocks, minerals, sediments, and fluids. The operational principles of this system are based on. X-ray fluorescence analysis is a method that uses characteristic X-rays (fluorescent X-rays) generated when X-rays irradiate a substance. Rob Thomas is the principal scientist at Scientific Solutions, a consulting company that serves the educational needs of the trace element user community.