Superb quality Calcite crystals on matrix with Chalcopyrite. We have all seen hundreds of these, but this one is exceptional, one of the best I can recall seeing in terms of glassy, gemmy crystals and freedom of damage. It's also a floater crystallized all around. I found one small crystal on the top rear (not part of the main group) that was incomplete, otherwise it is perfect. Just released from an old collection.