A significant percentage of China’s known tungsten resources is distributed in the Nanling area, a major tungsten polymetallic metallogenic belt located at the central-southern region of the South China Craton. The Yaogangxian tungsten deposit is one of the most important granite-related world-class tungsten deposits in the Nanling Range. Recent isotopic studies suggest the nature of mineralizing fluids by mixing between meteoric waters and exsolved fluids from the granitic magma which could have formed by crustal melting accompanied by crust-mantle interaction.

Based on mineral paragenesis and crosscutting relationships: stage 1 (early) wolframite–cassiterite–quartz veins, also termed “main-stage” veins, characterized by significant wolframite deposition; stage 2 sulfide–quartz veins, where abundant sulfide minerals were introduced during vein formation; and stage 3 fluorite–carbonate–quartz veins that resulted from the latest hydrothermal event and commonly crosscut earlier veins.

This is a good example showing the two most well-known Yaogangxian minerals in one specimen: early formed wolframite with post-forming fluorite (secondary growth: octahedron crystal included in the cubic xl), and some dolomite. Both fluorite and dolomite are partially coated by pyrite. It was a lucky find in 2019.

Fluorite and Dolomite on Wolframite

3cm, Yaogangxian mine, Yizhang County, Chenzhou, Hunan, China.

Tom Zhang Coll and Photo