CuFeS2::Au - 02.CB.10a (Strunz)
(from El Inglés Mine, Chancón, Rancagua, Chile)
This Chalcopyrite is special because it contains within about 150 ppm Gold (parts per million), I mean a high concentration of this precious metal. Has a brass and gold yellow color. From Chancón near from my native town. I took a photo at the entrance to the “El Inglés mine”, to see as it was.