Crystallographic orientation mapping of lizardite serpentinite by Raman spectroscopy

Abstract. The serpentine mineral lizardite displays strong Raman anisotropy in the OH-stretching region, resulting significant wavenumber shifts (up to ca. 14.5 cm?1) that depend on orientation of impinging excitation laser relative crystallographic axes. We quantified relationship between and using well-characterised samples Monte Fico by applying spectroscopy electron backscatter diffraction (EBSD) mapping thin sections polycrystalline grain mounts selected single crystals, as well a spindle stage study an oriented cylinder drilled from crystal. demonstrate main band region undergoes systematic shift depends inclination c-axis data are used derive empirical position this measured crystal: y=14.5cos 4 (0.013x+0.02)+(3670±1), where y is with respect normal vector (in degrees), x (wavenumber cm ?1) region. This new method provides simple cost-effective technique for measuring quantifying lizardite-bearing serpentinite fault rocks, which can be difficult achieve EBSD alone. In addition determine above relationship, we applicability orientations more complex sample deformed Elba Island, Italy.