WDXRF analysis of Iberian unfired potsherds from the Late Iron Age

Method

The outer surfaces of all the samples were mechanically removed prior to analysis.

The samples were heated to 950°C for one hour after 24h drying at 50°C, weighted for LOI calculation and ground in a tungsten carbide mortar. 0.8 g of powder was mixed with 3.2 g of Spectroflux 110 flux (Johnson Matthey; 33.5% metaborate and 66.5 % lithium tetraborate) and melted in gold-platinum crucibles with an autofluxer melting device (Breitländer).

The data were collected with a SRS 3400 (Bruker) spectrometer of 3 kW power (working at 60 kV, 100 mA max.). The spectrometer was equipped with a rhodium tube window, four analyser crystals (OVO-55, LiF200, LiF220, PET), two collimators (0.46° and 0.15°) and two sensors (a proportional Ar/CH4 gas-flow counter and a scintillation counter). The calibration of the instrument was carried out on 40 international certified reference materials.

Data description

• sample: sample reference;
• date: date of the analysis;
• laboratory: analysis laboratory;
• stratigraphy: stratigraphic unit (all dated to the first half of the 1st century BC);
• artefact: typology;
• part: analysed part of the artefact;
• LOI: loss on ignition (percent);
• CaO, Fe2O3, TiO2, K2O, SiO2, Al2O3, MgO, MnO, Na2O, P2O5: oxide mass percents;
• Zr, Sr, Rb, Zn, Cr, Ni, La, Ba, V, Ce, Y, Th, Pb, Cu: ppm.

Data below the following limits should be considered unreliable:

• Na2O: 0.5 %
• La: 24 ppm
• Y: 15 ppm
• Th: 15 ppm
• Pb: 20 ppm
• Cu: 10 ppm