MINERALOGICAL CHARACTERIZATION OF BLUSH

Field-based reflectance spectroscopy is a developing technique with major applications to crime scene investigations and forensics due to its ability to detect distinct signatures from minerals and mineral-based products on materials. Many cosmetics are mineral-based, meaning that reflectance spectroscopy could be used to trace contact between skin with make-up on it and areas of a crime scene or other person. This creates an application for the technique in collecting evidence for cases of violence against women and others who wear make-up. Wet n’ Wild blush has been used as a starting point for study. The mineralogy of the blush has been characterized using powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive spectroscopy (EDS) to better understand the components of cosmetics and provide context for further studies using reflectance spectroscopy. Both pack and smear mounts of the cosmetic were made for PXRD analysis, which identified talc, muscovite, rutile, goethite, quartz, chlorite, barite, and lazurite (a component of ultramarine pigment) as the main phases. Supplemental EDS confirmed these matches by chemistry, and both SEM and TEM have been used to image the powder. The texture of the powders is varied and dominated by platy particles of talc and muscovite, however fiber-like morphologies were observed. A variety of other habits that include spherulitic and amorphous occurred with other minerals. Results provide detailed mineralogical constraints for trace forensic analysis of this common blush. Overall, this mineralogical characterization provides a framework for a novel study on the reflective spectroscopy of the blush as an exemplar material as it is easily applicable to a variety of other cosmetic types for future studies. Results provide some context for studies of counterfeit products and contamination for this and other cosmetic samples. Further study is warranted.