Application of Raman imaging and scanning electron microscopy techniques for the advanced characterization of geological samples.

Raman is an important tool for diagnosing minerals in geoscience. However, smaller magnification of optical microscope assembled in conventional Raman spectroscopy limits the application of Raman in sub-micro and nano scale. Raman imaging and scanning electron microscopy (RISE) combine the advantage of scanning electron microscope and Raman spectroscopy, which can collect the morphology, composition, and structure information in the same micro region of the geological sample in situ. In this paper, we introduce the development and working mechanism of RISE, and carried out some typical applications in different research of geoscience. The purpose of this review is to allow readers to understand the basic principles and application potential of RISE in geoscience. Finally, we briefly point out current challenges faced by this technology and some research directions in the future. HIGHLIGHTS: Raman imaging and scanning electron microscopy as potential method was proposed for the research on geosciences. Common polymorphism and isomorphism were distinguished clearly in situ. A new research route for tiny inclusion and organic matter in situ was developed.