title: Innovative analytical methodology combining micro-x-ray diffraction, scanning electron microscopy-based mineral maps, and diffuse reflectance infrared fourier transform spectroscopy to characterize archeological artifacts.
abstract: Excavations at the 14th century Moorish rampart (Granada, Spain) unearthed a brick oven alongside black ash and bone stratigraphic layers. In situ evidence suggests the oven served to fabricate a wall coating including powdered burnt bones. Original ad hoc analyses improved on conventional methods were used to confirm this hypothesis. These methods enable (i) nondestructive micro-X-ray diffraction (mu-XRD) for fast mineralogical data acquisition (approximately 10 s) and moderately high spatial (approximately 500 microm) resolution and (ii) identification and imaging of crystalline components in sample cross-sections via mineral maps, yielding outstanding visualization of grain distribution and morphology in composite samples based on scanning electron microscopy-energy dispersion X-ray spectrometry (SEM-EDX) elemental maps. Benefits are shown for applying diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) vs transmittance-FT-IR (T-FT-IR) to analyze organic and inorganic components in single samples. Complementary techniques to fully characterize artifacts were gas chromatography/mass spectroscopy (GC/MS), optical microscopy (OM), conventional powder XRD, and (14)C dating. Bone-hydroxyapatite was detected in the coating. Mineralogical transformations in the bricks indicate oven temperatures well above 1000 degrees C, supporting the hypothesis.
authors.affiliation: Department of Mineralogy and Petrology, Faculty of Science, and Scientific Instrumentation Centre, University of Granada, Campus Fuentenueva s/n, 18071 Granada, Spain. cardell@ugr.es
authors.forename: Carolina
authors.initials: C
authors.lastname: Cardell
authors.forename: Isabel
authors.initials: I
authors.lastname: Guerra
authors.forename: Julia
authors.initials: J
authors.lastname: Romero-Pastor
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Cultrone
authors.forename: Alejandro
authors.initials: A
authors.lastname: Rodriguez-Navarro