Mineralpedia Details for Eugenite
Named for Professor Eugen Friedrich Stumpfl, an Austrian mineralogist at the Mining University in Leoben, Austria, to honor his work on noble metal compounds. Eugenite is a rare mineral that can be found in cuprite and in low-grade copper sulfide ores in shales and carbonate rocks. Localities for Eugenite include notably in Poland, and the United States, with a few other known localities. Eugenite can be found in association with chalcocite, covellite, tennantite, hematite, calcite, ankerite, and gypsum.
Ref. Handbook of Mineralogy, Anthony et al (1995) and MSA at http://www.handbookofmineralogy.org/pdfs/eugenite.pdf
Eugenite from Los Bordos mine, Elisa de Bordos, Copiapo, Atacama, Chile
Silvery, malleable thin veinlets on matrix.