Raman spectroscopy as a powerful tool for estimating the chromium to aluminum content in a range of different chromites

Raman spectroscopy has been applied to study a range of chromites with variable chromium to aluminum to iron contents to determine conclusions about possible correlations between the chromium concentration and the position of the main Raman peaks within this mineral. It was found that a negative correlation exists between the chromium number, calculated from electron microprobe data, and the Raman peak number. Chromite grains with high chromium number show a low Raman peak, whereas samples with low chromium numbers show a higher Raman peak. Therefore, it was possible to infer a relationship between the mineral composition and Raman bands for this type of mineral. The measurements have clearly shown that it is possible to draw conclusions about the chromium content of the mineral based on the Raman peak alone. This shows that in simple chemical compositions, such as in chromites and olivines, the peak positions can provide initial information about the compositions of the minerals. Thus, it is possible to use Raman spectroscopy as a simple and fast investigation method, which we could proof on very different materials. This outcome supports a possible application of portable Raman devices on Earth or in space, i.e. for asteroids and/or other planets. Raman spectroscopy has more over proven to be a quick and powerful method to identify minerals and a lot of other materials investigated in the mineralogical state collection Munich. Therefore, we have also created a new in house Raman database (MSM_RMD = Mineralogical-State-Collection-Munich_Raman-Mineral-Database) for minerals, plastic, ore minerals and other materials.