Occurrence Characteristics of Gold and the Typomorphic Characteristics of Pyrite in the Yizhuxiang Gold Deposit of the Daduhe Metallogenic Belt

Objective Orogenic gold deposit is widely developed in the Daduhe gold metallogenic belt. The Yizhuxiang gold deposit is one of the representative medium-sized deposits in the Daduhe gold metallogenic belt. Pyrite is the main gold-bearing mineral in the deposit, and its formation period is obvious, providing an ideal example for understanding the mineralization of this orogenic gold deposit. Method Based on detailed field work, this article conducted a comprehensive study on the ore samples of the Yizhuxiang gold deposit, including mineralogical observation, electron probe analysis, pyrite thermoelectric property testing, and pyrite trace element analysis, to explore the occurrence state of gold minerals in the ore and the typomorphic characteristics of pyrite. Result The gold minerals in the deposit are mainly natural gold, presenting as microscopic gold, with generally high fineness. They mainly exist in the form of inclusion gold and fissure gold in pyrite and its fissures, and some are found in chalcopyrite and bismuth tellurite as inclusion gold. Conclusion The main gold-bearing minerals in the deposit are pyrite and chalcopyrite. Gold mainly exists in pyrite in the form of inclusion gold and fissure gold. Pyrite basically does not contain lattice gold and nano-gold. The bismuth telluride (Te-Bi-S) melt represented by bismuth telluride may have an enriching effect on gold. The calculation results of the thermoelectric coefficient of pyrite in the deposit show that the crystallization temperature of pyrite is approximately 278 ℃, and it is speculated that the deposit belongs to a high - to medium-temperature hydrothermal deposit. Through the analysis of thermoelectric properties, it is possible that the ore body has been eroded to a certain extent.