Here we have a superfine and well crystallized old-time specimen of rare silver and gold telluride Sylvanite. It is known at its best for this surreal, metallic-organic growth that seems to have pattern, when crystallized at we see here. More technically speaking, these are flat-lying crystals in the form of typical graphic intergrowths ("Schrifterz"). The effect is bizarre, and beautiful. According to MINDAT: Named after the Transylvania region of Romania, where it was first found, and Sylvanium, one of the names proposed for the newly discovered element tellurium, which it contains.