Analytical study of waterlogged ivory from the Bajo de la campana site (Murcia, Spain)

摘要: Abstract This work reports an analytical study conducted prior to the conservation intervention of a collection elephant tusks excavated from wreck site 600–500 BC Phoenician trading vessel in Bajo de la campana (Murcia, Spain). The state ivory, determined by prolongated immersion marine environment, was established multi-technique methodology: light microscopy, field emission scanning electron microscopy–X-ray microanalysis (FESEM–EDX), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), spectrophotometry and gas chromatography–mass spectrometry (GC–MS). analyses demonstrated that structure composition both tusk parts, namely inner ivory outer cementum, were altered due characteristic diagenetic processes environment. Ca enrichment observed which gave higher Ca/P molar ratio values than for ideal hydroxyapatite. Mg leaching observed, together with uptake exogenous elements (F, Cl, Si, Al, S, Na, Fe, Cu, Sr, Pb, Sn, Ag, V, Ni, Cd Zn), prevalently identified external part. Uptake S Fe associated neoformation pyrite framboids. high carbonate content measured FTIR, agreed ratios found archaeological tusk, ascribed substitution phosphate groups (type-B) bioapatite accompanied some authigenic calcium infilled ivory. An increased degree crystallinity when comparing several indices those modern used as reference material. Increased took place cementum. In accordance crystallinity, HPO 4 2 − index indicated hydrated layer nanocrystals diminished All these changes correlated significant organic matter loss reported tusk. Interestingly, remaining collagenous noticeably glycine depletion acid amino acids. Changes secondary proteins also recognised collagen gelatinisation. addition proteinaceous materials, small amounts long-chain fatty acids, monoglycerides cholesteryl oleate GC–MS. Cholesteryl blood, could have precipitated at time specimen death. identification large framboids oleic acid/palmitic suggested minimal oxidative degradation processes, probably slightly anoxic conditions underwater