NON-INVASIVE CHEMICAL INVESTIGATION ON STONE ARTIFACTS IN ANCIENT GUATEMALA

 

Yoshiyuki Iizuka (Academia Sinica, Taiwan)

Tomás Barrientos Q. (Universidad del Valle de Guatemala)

Andrea Sandoval (Universidad del Valle de Guatemala)

Pablo Estrada(Universidad del Valle de Guatemala)

Shintaro Suzuki (Okayama University)

 

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A portable X-ray Fluorescence spectrometer (p-XRF) is handy and completely non-invasive technique to study for chemical compositions of stone artifacts. On-site chemical investigation by the p-XRF is carried out for stone artifacts from representative archeological sites from the Lowlands (La Corona), though the Highlands (Kaminaljuyu and Atitlan) to the Pacific Coast (Monte Alto) in Guatemala. Greenish jadeite jade (jadeite and omphacite) artifacts are major components from the La Corona site, whereas stone artifacts from the Highlands and the Pacific Coast areas are made of various kind green rocks which including monomineralic rocks of jadeite, serpentine, mica, amazonite (K-feldspar), anorthite, and pyrophyllite as well as volcanic and metamorphic rocks. Until now, the most kind of greenish stone artifacts have frequently been described as simply “greenstone” or “Jade” without lithic analytical evidences; however the results revealed that different kinds of greenish rocks were used by the Prehispanic populations. Since jadeitite (jadeite jade) deposits only located along the Motagua Fault zone in central Guatemala, it is widely accepted that the central Guatemala is the quarry of jadeitite in the Mesoamerica, but many potential resources of all the utilized rocks, here revealed, are still unknown. We also studied metallic materials from several site through the same method and identified, black in color, goethite (FeO[OH]) pseudomorphs after pyrite (FeS2). There are used to called “pyrite” but identified now that some of ornaments, mirrors and dental inlays are made of goethite. These finding should open a new regional perspective about exploitation of various lithic materials as well as their sourcing.

 

(Talk in Japanese)