Corrosion analysis of unearthed jade from Daye Zhen Tomb of Northern Zhou Dynasty

Abstract

X-ray fluorescence spectroscopy, scanning electron microscopy energy spectrum, excitation-emission matrix spectroscopy, and Fourier transform infrared spectroscopy was applied to the unearthed jade with multilayered corrosion, to reveal the microstructure, composition structure, and distribution of organic matters. Our results showed that the interior of the jade was mainly composed of layered serpentine with a regular structure, while the white layer structure on the surface is scattered and irregular, and the content of calcite formed by elements Ca and C increases significantly; between the green matrix and the white layer on the surface, there are brown corrosion zones with obvious fluorescence effect and mainly composed of humic acid, which continuously extends inward along the corrosion cracks for accelerating the internal corrosion. This article, for the first time, argued for the corrosive and fluorescent humic acid bands that appear inside serpentine jade and cautions its role in investigating the corrosion of jade.

Identification of microbial diversity in buried ivory soil at the Sanxingdui site in Guanghan City, China, using high-throughput sequencing

“…Notably, the composition of ivory, particularly its organic components, provides an ideal growth environment for microorganisms. The acidic substances and enzymes produced by microbial metabolism in the buried environment have a corrosive effect on ivory, resulting in its dissolution and the release of minerals, which has a non-negligible effect on the long-term stable preservation of ivory (Yu et al, 2023;Zhang et al, 2023Zhang et al, , 2024. This corrosion process may accelerate ivory deterioration and destroy its original firmness and structural integrity.…”