Plant-based red colouration of shell beads 15,000 years ago in Kebara Cave, Mount Carmel (Israel).

Decorating the living space, objects, body and clothes with colour is a widespread human practice. While the habitual use of red mineral pigments (such as iron-oxide, e.g.

Chemical characterization of inks in skin reactions to tattoo.

Skin reactions are well described complications of tattooing, usually provoked by red inks. Chemical characterizations of these inks are usually based on limited subjects and techniques. This study aimed to determine the organic and inorganic composition of inks using X-ray fluorescence spectroscopy (XRF), X-ray absorption spectroscopy (XANES) and Raman spectroscopy, in a cohort of patients with cutaneous hypersensitivity reactions to tattoo.

Assessing the carbonisation temperatures recorded by ancient charcoals for δC-based palaeoclimate reconstruction.

Ancient charcoal fragments, produced by the use of wood as fuel in archaeological contexts or during natural or anthropic forest fires, persist in soil and sediments over centuries to millennia. They thus offer a unique window to reconstruct past climate, especially palaeo-precipitation regimes thanks to their stable carbon isotope composition. However, the initial δC of wood is slightly modified as a function of the carbonisation temperature.

Raman and ATR-FTIR analyses of medieval wall paintings from al-Qarawiyyin in Fez (Morocco).

A multi-analytical study has been undertaken to characterise wall paintings from the al-Qarawiyyin university in Fez, dating back to the 9th century and still in activity, with the aim of identifying the pigments used and going back to the painting techniques adopted by the Moroccan craftsmen of the time. The investigation crossed Raman and ATR-FTIR structural analyses along with XRF elemental ones, as well as colorimetric measurements. The colours and shades of six representative fragments collected during a recent excavation have been examined.

Spectral characterisation of a traditional Mesoamerican dye: relationship between identification on the 16 century manuscript and composition of plant extract.

Characterisation of vegetal colourants in manuscripts is still a challenging task. Their identification using non-invasive techniques - since sampling is rarely possible - is valid only if there is evidence that the recorded signals are generated by compounds specific to the plant species. Otherwise, more extensive chemical characterisations are required to relate the non-invasive technique signals to the chemical composition of the dye extract and thus avoid misidentification.