The natural pigments used in Costa Rica: preliminary analysis of geomaterials and polychromic ceramic shred from Guanacaste

Abstract

In this publication, we provided data on the main sources of pigments published in the scientific literature. Furthermore, the geomaterials used nowadays in the Guaitil area (Costa Rica) and six types of ceramic fragments coming from different Costa Rican archaeological sites (Jicote Policromo, Jicote variedad felino, Birmania Policromo, Mora Policromo variedad Chircot, Altiplano Policromo, Mora Policromo variedad Guapote types) were characterized using X-ray fluorescence analysis (XRF), infrared spectrometry (FT-IR) and scanning electron microscope (SEM-EDS). In the geomaterials used by Guaitil potters as pigments, (i) the red and white materials were kaolinites with quartz and traces of iron oxide, and (ii) the black pigment was a mixture of quartz, manganese oxides, hematite and trace of kaolinite. In the case of the pre-Columbian ceramics, the polychrome Altiplano and Mora Policromo engobes were composed of meta-caolinite, meta-esmectite and quartz, while the Jicote Polychromium pot included meta-smectite, crystobalite, anhydrite and hematite in its chemical composition. The red pigments were made with the mixture of the slip with hematite-rich geomaterial, manganese oxide or magnetite depending on the color and the ceramic style.