Ceramic vessel 1. Grave 36. Cemetery of Piquía

Raman Microscopy

Mineral analysis of the red decoration

Non destructive. Surface cleaning. Sample pretreatment is not required. Direct measurement.

Micro-Raman Spectroscopy (MRS)

Portable equipment: BWS445-785S innoRam™ Raman spectrometer (B%26WTEK, Inc., Newark, USA) with a 785 nm excitation laser (maximum power of 300 mW) and a 4.5 cm-1 spectral resolution. The Raman microprobe can be mounted on a tripod with motorized XYZ axis (MICROBEAM S.A, Barcelona, Spain) or on a microscope sampling stage (B%26WTEK, Inc., Newark, USA).

X-Ray Fluorescence

Elemental analysis of the red decoration

Non destructive. Surface cleaning. Sample pretreatment is not required. Direct measurement.

Energy dispersive X- ray fluorescence (EDXRF);

EDAX (model Eagle III) fluorescence spectrometer (CITI, University of Seville). This spectrometer is equipped with a microfocus X-ray tube with an Rh anode, a polycapillary lens for X-ray focussing, and an 80 mm2 energy dispersive Si-(Li) detector. The sample chamber incorporates an XYZ motorized stage for sample positioning. A high resolution microscope is used to position the sample on the desired distance from the polycapillary. To increase the sensitivity of the low Z elements, the sample chamber can be brought under vacuum. For the analysis of the samples, a spot size of 300 μm was chosen at an operating X-ray tube voltage of 40 kV. The tube current was adapted for each sample in order to optimise the detection of X-rays;