Application of Electron Microprobe to Study the Features of Tellurides in the Jinqingding Gold Deposit, Shandong Province

A systematic study of the phase composition and element occurrence characteristics of tellurides in tellurium-bearing gold deposits will be helpful for the genesis understanding of gold deposits of this type and for prospecting exploration. Tellurides in the Jinqingding gold deposit are too small and are difficult to identify. Previous research lacked the detailed studies of the element distribution characteristics of tellurides. In this study, the types, symbiotic relationship, chemical composition and element distribution characteristics of tellurides in the deposit were analyzed by electron probe using BSE, WDS, EDS and mapping modes. Results show that petzite is closely associated with hessite and intergrowths of these two minerals are common. Au and Ag are unevenly distributed in the intergrowths, and calaverite shows as a bright spot in the scanning map. Tellurium is always likely to combine with Ag to form hessite. With the consumption of Ag, petzite began to appear and Te combined with Au to form calaverite after exhausting Ag in magmatic hydrothermal fluids. The superfluous Au in the hydrothermal fluids at the later stage of mineralization reacted with hessite or petzit to produce unconventional tellurides, finally forming a native gold. The growth of gold-silver minerals follows the sequence, hessite, petzite, calaverite, and Au from early to late. This study provides technical support for the comprehensive utilization of tellurium-bearing gold deposits.