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. When exposed to X-rays, a sample emits characteristic secondary (fluorescent) X-rays that are unique to each element. Fluorescent X-rays are electromagnetic waves that are created when irradiated X-rays force inner-shell electrons of the constituent atoms to an outer shell and. This booklet gives a general introduction to X-Ray fluorescence (XRF) spectrometry and XRF analysis. It is intended for people new to the field of XRF analysis. There are two main types of XRF spectrometers. EDXRF is fast and portable, while WDXRF gives detailed and precise results.