This wonderful copper specimen from the Central Mine, Keweenaw, Michigan measures 7.5 by 6 by 3 cm. It does not appear to have ever been cleaned, which is my preference with these historic old copper specimens. There are MANY nicely formed sharp copper crystals growing arborescently one off the next. Tucked in the middle of the front are several super crystals rising perpendicularly off the plate. This piece stands by itself, is wonderfully crystallized on both sides and has no damage.