Carrollite is now fairly common... although it has been seldomly found, there were a few big pockets found at this amazing location, though they were decades ago. This is from the pocket of the late 1990s, and it was chosen at the time for balance, perfection, and size for a large thumbnail of competitive quality, from the hundreds available at that time. It stands up, today, even despite a few new finds since of generally single crystals. The sharpness, isolated crystal aesthetics, and delicate positioning on matrix makes this a superior thumbnail specimen for the discerning collector, who needs a great specimen that happens to be a thumbnail - not just a carrollite that happens to fit in a regulation TN box. It is ridiculously lustrous, sharp, and three-dimensional. Better in person, although the photo hopefully conveys it as well. Purchased from Brice and Christophe Gobin when they had the best pocket of the species on display, in the late 1990s at the old Tucson show hotel. Lastly, as a note, the calcite is not a cleaveage fragment, but seems to be a bit etched as a natural crystal floater.