Calcite with Chalcopyrite

A fellow I know lives near the Trend and always brings me some good pieces he has wrangled from the miners. The composition of this exquisite specimen made it a no brainer. Two doubly terminated 6+cm crystals, one sceptered, fall perfectly on a limestone matrix replete with small irridescent chalcopyrites. If you don’t have a good one this may be it!

Locality: Sweetwater Mine, Viburnum Trend, Reynolds County, Missouri

Composition: calcium carbonate