Electron microprobe analysis

The electron micro probe analyser (EMPA), is an analytical tool used to non-destructively determine the chemical composition of small volumes of solid materials. It works similarly to a scanning electron microscope: the sample is bombarded with an electron beam, and signals that come from the sample are collected. This enables the elements present within sample volumes of 10-30 cubic micrometers or less to be determined.

sphalerite (G1); galenite (G2); iron oxide-hydroxide-sulphate (G3, G4)‏