Cu-Zn alloy
Herzog Julius smelter slag locality, Astfeld, Langelsheim, Goslar District, Lower Saxony, Germany
SEM-EDS analysed (about 70 at.% Cu, 30 at.% Zn); Chris Auer photo and collection, swapped in 1989 (labeled as gold - similiar to the "gold" from the Gertraudi smelter https://www.mindat.org/loc-57140.html )
© AC