An outstanding and extremely rare specimen of pseudomorph of pyrite after sphalerite and chalcopyrite, on quartz.. Giudurska mine, Erma reka, Zlatograd area, Bulgaria
An excellent specimen of galena cubic crystals, overwrought by chalcopyrite and followed by sphalerite and quartz
One very nice , cabinet size specimen of well terminated cubic pyrite crystals, covered by quartz strongly oxidated to bornite in some parts of the specimen.
An aesthetic cabinet sized specimen of large chalcopyrite crystals, singenetically developed with galena and sphalerite, followed by quartz. In the last stage of crystallization, oxidation creates a thin coating of bornite and covellite.