Extreme iron isotope variation of pyrite in the Muping gold deposit, Jiaodong: Implication for tracing metal origin

•A wider δ56Fe variation of pyrite was determined by in-situ analysis.•The most negative δ56Fe value of nature pyrite occurred in the Muping gold deposit.•Kinetic isotope fractionation occurred at Muping and has a significant impact on δ56Fe of pyrite.•Kinetic isotope effect ultimately has no obvious effect on source tracing of hydrothermal gold deposit.