This is an exceptionally large and heavily included calcite crystal, with minute dispersed bits of copper giving the calcite itself a rich copper background color overall, AND still showing you bright flecks of native copper inside. Copper included calcite is a highly desired combo, from Michigan's historic Copper Country. It is not unique to Michigan per se, but this is nevertheless where the best come from. Came from, rather...mostly in the late 1800s and early 1900s. Specimens of this size, preserved in such condition, are uncommon today. This one has a pristine termination which is decorated by a native copper crystal perched on its left edge as an accent - most unusual! The calcite is clean and glassy, with no damage. It is a very beautiful display piece simply on its own merits, history and rarity aside. As an extra accent, it has a little outgrowth of quartz crystals at its base. This specimen was obtained from collector Phil Scalisi in the 1990s. It was said to have been in the Arthur Montgomery collection (though no label survives). Recently ex George Elling collection. Joe Budd photos