Copper crystal from the Mohawk Copper mine,Keweenaw county,Michigan. It has a dark iridescent  patina to it from the arsenic content in the Copper from this location, the mine has been posted for many years now,too bad. It is 3 1/8" x 1 3/16" x 3/8" and has been etched with acids to remove the Calcite and minor Quartz that was on it. Buyer pays all shipping by small flat rate box or international postal codes and extra  insurance if requested and will combine items for cheaper shipping cost.  Thanks for looking and look at our store for other mineral  specimens and Lake Superior Copper banded/replacement Agates and Copper included Agates some of the oldest and rarest Agates on the planet.