These hoppered copper crystals are from the Central Mine in Central, Keweenaw County, Michigan, USA. This piece is double terminated and it consists of complex hoppered copper crystals that are free from matrix. They are large crystals that measure up to 1 inch across. It can be displayed from all sides and angles. Photo 2 shows a pseudo-cubic habit. They have a reddish to iridescent patina.. This piece measures 1 13/16 x 1 1/2 x 1 1/8 inches or 46 x 38 x 28 mm.