The black tellurides associated with gold in the San Juans of Colorado are routinely labeled petzite, as was this one. But so far, in all the specimens I have had analyzed, they have been hessite every time. This one has tiny lustrous black rounded crystals of hessite with gold in a vug in white quartz. The gold is also shot through the massive quartz matrix. From the collection of Erberto Tealdi, the former editor of the Italian mineral magazine Rivista. Hessite confirmed by EDX.