This “sedimentary copper” is from the Caribou Dome Prospect, Valdez Creek District, Matanuska-Sisitna Borough, Alaska, USA. This prospect is not producing but has been explored for its copper mining potential. It contains ten different minerals including copper and chalcopyrite and pyrite. This piece is referred to as sedimentary copper because it was laid down in banded layers (visible in photo3). It has a copper to bronze appearance and has been polished to a sub metallic luster on the top and one end. Although it is called copper it is actually finely bedded massive chalcopyrite and pyrite with possibly some copper mixed in. This piece measures 3 1/2 x 3 1/4 x 1 3/4 inches or 90 x 83 x 44. It weighs over 1.5 pounds.