Existing forms of REE in gold-bearing pyrite of the Jinshan gold deposit, Jiangxi Province, China

Rare earth element (REE) is widely used in various fields of geology. Study of the existing forms of REE in geological objects is a necessity for us to solve geological problems related with REE. This paper tried to make it clear the existing forms of REE in gold-bearing pyrite in Jinshan gold deposit by stepwise dissolution test with ICP-MS analysis. Results showed that content of REE in fluid-inclusions of gold-bearing pyrite was very low, which only took about 0.07%–0.70% of the ∑REE, and that of pyrite phase took about 4.87%–17.00%, whereas higher REE contents of studied pyrites were mainly from Zr-rich silicate micro-mineral phase wrapped in sulfides, i.e., 82.30%–94.99%, which basically controlled the REE contents of pyrite. The REE contents in silicate phase accounted for part of ∑REE of the original liquids from which pyrite crystallized and was separated out. Therefore, the REE composition in pyrite mineral can be considered as the reflection of the composition of pyrite-forming fluid. It is thus possible to trace the sources and features of ore-forming fluid by studying the characteristics of REE in pyrite.