A truly unusual specimen! This calcite, doubly-terminated and in a cluster of smaller calcites, somehow glommed onto one of those usually floater etched corners, formed from strange chemical processes in which large cubic fluorites from this mine sometimes decay into 4 corners that then come apart and fall gently into the pocket over time. Somehow, the corner must have gently landed on this calcite as it was forming, as the two are intergrown and totally attached. The fluorite must have formed long before, thus. This fluorite corner is complete and features the full stalk into what would have been the center of a cube. It has the sharp corner, however, remaining...when I was a kid some people labeled these as "fluorite pseudo after calcite," because they looked so crudely scalenohedral themselves. But, they really are fluorites, just of odd form. Try finding another one in matrix! Let me tell you, they are rare anyways in a cluster or attached to fluorite, but VANISHINGLY rare attached to calcite like this! And, aesthetically attached, to boot.