This native copper/silver halfbreed nugget is from the Keweenaw Copper Mining District in Keweenaw County, Michigan, USA. Keweenaw County contains hundreds of once operational mines and unnamed copper deposits with a long history that predates colonial times. It produced millions of tons of copper and has over 150 associated mineral species. The district produced some of the finest copper and silver specimens known.This piece or nugget is a natural combination of both native copper and native silver. This piece measures 1 1/4 x 13/16 x 1/2 inches or 33 x 21 x 12 mm.