Backscattered electron images, X-ray maps and Monte Carlo simulations applied to the study of plagioclase composition in volcanic rocks

► High resolution maps of anorthite content in single plagioclase crystals were obtained. ► The procedure was tested on volcanic rocks and is suitable for more evolved plagioclases. ► The ultimate resolution of X-rays and BE signal were studied by Monte Carlo simulations. ► MC simulations allowed to explain the BE contrast enhancement due to interface crossing.