A review of Te and Se systematics in hydrothermal pyrite from precious metal deposits: Insights into ore-forming processes

Pyrite chemistry: A new window into Au-Te ore-forming processes in alkaline epithermal districts, Cripple Creek, Colorado

In hydrothermal ores, gold is commonly hosted by sulfide minerals due to its affinity for reduced sulfur. In contrast, the occurrence of gold in oxide minerals remains poorly documented and incompletely understood. In this contribution, we demonstrate that magnetite can be a significant host mineral for gold. Skarn ores from the giant Beiya Au deposit (323 t Au at 2.47 g/t), southwest China, contain abundant nanometer- to micronsized gold hosted by magnetite. A range of bismuth minerals (e.g., native bismuth, maldonite, and bismuthinite) occur within the same assemblage. Textural and mineralogical studies as well as thermodynamic modeling indicate that Bi melts scavenged Au from hydrothermal fluids during magnetite growth. Fluctuating f O 2 ( g ) at the surfaces of crystallizing magnetite led to the precipitation of Bi-Au melt, ongoing gold refinement, and entrapment of gold and bismuth minerals within magnetite. Sulfidation of Bi, triggered by increased sulfur content and/or decreased temperature, further promoted gold precipitation. Bismuth melts are interpreted to have played a crucial role in Au enrichment from gold-undersaturated fluids at Beiya. The results imply that magnetite-rich systems are also potential targets for Au exploration and extraction, particularly in cases where coexisting Bi minerals are observed in abundance.

Nano- to micron-scale particulate gold hosted by magnetite: A product of gold scavenging by bismuth melts

Love is in the Earth: A review of tellurium (bio)geochemistry in surface environments

The North China Craton contains voluminous gold deposits, which occur within the Northern Margin Gold Belt, the Southern Margin Gold Belt, and the Jiaodong Gold Province. However, relatively little...

Desen Zhang

Papers

Hydrothermal alteration and ore-forming fluids associated with gold-tellurium mineralization in the Dongping gold deposit, China

Ore petrography and chemistry of the tellurides from the Dongping gold deposit, Hebei Province, China