engleski

Biomineralization on an Ancient Sculpture of the Apoxyomenos: Effects of a Metal-Rich Environment on Crystal Growth in Living Organisms

A rare bronze sculpture of the male athlete Apoxyomenos, dating from about the 2nd century BCE, was found submerged in the Adriatic Sea off the Croatian coast, in 1998. The influence of this specific artificial surface on the crystal phase of encrusted calcareous structures of biomineralizing marine organisms was probed. ICP-AES analysis showed all samples to have a high metal content, with the specific metals and their concentrations being consistent with the sculpture as the source rather than normal seawater. No metal-based crystalline phases were found by powder X-ray diffraction apart from the presence of iron and copper hydroxides in one sample that showed a distinctly green coloration. XRD analysis indicated that calcite, magnesium calcite and aragonite were the dominant phases in all cases, with minor or trace phases of albite, microcline and mineral quartz. The phase compositions of these biomineralized structures were significantly different from those of the same organisms living in putatively unpolluted environments. The accumulation of non-native metals in the calcareous structures of these organisms and the unusual phase compositions of the latter suggest metal-induced changes to the biological pathways controlling the transport of calcium and magnesium and incorporation of heavy metals at inorganic matrix growth sites.

biomineralization ; crystal growth ; metal ; bio-corrosion ; apoxyomenos

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