Te-rich magmatic-hydrothermal systems in northeastern Greece and Sardinia: a comparative study of ore mineralogy and sulphidation state.

In the studied districts, the association of hessite, stutzite, sylvanite, petzite, goldfieldite, coloradoite and altaite with native tellurium indicate direct magmatic inputs to the mineralising solutions. The sulphidation states of the telluride-bearing ore fluids fluctuated between intermediate and high even within the same deposit: in the NE Greek deposits, tellurides are present in porphyry-related base-metal veins as well as in intermediate- and high-sulphidation assemblages in the epithermal environment, while in the Furtei mine, the only Te-rich Sardinian system, the tellurides are also related to both high- sulphidation and intermediate-sulphidation assemblages. A relationship between the sulphidation state and the timing of bulk ore introduction seems probable.
In the studied districts, the association of hessite, stutzite, sylvanite, petzite, goldfieldite, coloradoite and altaite with native tellurium indicate direct magmatic inputs to the mineralising solutions. The sulphidation states of the telluride-bearing ore fluids fluctuated between intermediate and high even within the same deposit: in the NE Greek deposits, tellurides are present in porphyry-related base-metal veins as well as in intermediate- and high-sulphidation assemblages in the epithermal environment, while in the Furtei mine, the only Te-rich Sardinian system, the tellurides are also related to both high- sulphidation and intermediate-sulphidation assemblages. A relationship between the sulphidation state and the timing of bulk ore introduction seems probable.