Pictured above is the largest leaf of vein copper from the White Pine Mine in Ontonagon County, Michigan. It measures some eight feet across and is shown here on display in the Hall of Gems and Minerals at the Smithsonian’s Museum of Natural History. This specimen is from the stratified sedimentary rock deposit called the Nonesuch Shale that formed during the late Keweenawan age. Some of the surrounding shale is still attached, along with imprints of ancient water ripples. Click on the image to see them more clearly.