Testing ceramic pigment recipes: experimental design and first results for red hues from Fiambalá region (Tinogasta, Catamarca) Probando recetas de pigmentos cerámicos: diseño experimental y primeros resultados para los rojos de la región de Fiambalá (Tinogasta, Catamarca)

MARA BASILE; ELEONORA FREIRE ESPELETA; MARIA ELBA REINOSO; ROSSI, MICAELA; EMILIA B. HALAC; NORMA RATTO

Revista del Museo de Antropologia

Universidad Nacional de Cordoba, Facultad de Filosofia y Humanidades

Lugar: Cordoba; Año: 2023 vol. 16 p. 65 - 78

Archaeometric results (Raman spectroscopy and X-ray diffraction) achieved by an interdisciplinary group of archaeologists, physicists and chemists show that the same base compound (hematite: α-Fe2O3) was employed to obtain red paints with a wide palette of tonalities, as the ones observed in slips and designs from recovered pottery pieces in Fiambalá and Chaschuil regions, dating from the 1st to the 16th centuries AD. These results raised questions, which prompted an experiment to evaluate the influence of the firing temperature on both chemical composition of paints and resulting hue. A two stages experiment, differing in the firing method (muffle furnace and direct-draft clay oven), was conducted under controlled conditions of observation, recording, and analysis. Building upon the preliminary results, some variations were conducted to assess the impact of firing time at each temperature and the inclusion of organic binders in the recipes. Results point out hematite as the cause of red tones in all cases. No significant chemical changes were detected in the pigments, whether fired at 750 or 900 °C, or in those maintained at these temperatures for periods ranging from 0 to 20 minutes. Additionally, the binders had no impact on the composition or the resulting tonalities.