Analytical methods, formation, and dissolution of cinnabar and its impact on environmental cycle of mercury

ABSTRACT

Mercury sulfide (HgS, cinnabar, and metacinnabar) is a major Hg sink, widely available in various environmental compartments. The formation and dissolution of HgS play a crucial role in the geochemical cycle of Hg, including its transport, reduction, methylation, and toxicity. Unlike other Hg species (e.g., methylmercury, Hg⁰), environmental HgS occurs in the form of different sized particles, leading to various challenges regarding its quantification and the evaluation of potential environmental impacts. This review summarizes the current analytical methods for the identification, characterization, and quantification of HgS, including sequential chemical extraction, X-ray absorption spectroscopy, programmed thermal desorption, and selective vapor generation, among other methods. In addition, the chemical/biological pathways and mechanisms involved in the formation and dissolution of HgS are reviewed, as are the analytical and environmental perspectives of HgS. This review furthers our understanding and encourages the study of the environmental formation and dissolution of HgS and its role in the geochemical cycle of Hg.

KEYWORDS:

• Cinnabar
• mercury
• sulfidation

Additional information

Funding

This work was supported by the National Basic Research Program of China under Grant 2013CB430002, National Natural Science Foundation of China under Grant 21522705, 21377156, 21777178, and 21677061, and Key Projects for Frontier Sciences of the Chinese Academy of Sciences under Grant QYZDB-SSWDQC018. The authors thank the Museum of China University of Geosciences for providing the metacinnabar ore specimen for imaging. Y.Y. acknowledges support from the Youth Innovation Promotion Association of the Chinese Academy of Sciences.