These specimens from the La Viesca mine are very rare and appeared in the middle of the last decade. It is a very bright specimen formed mainly by cubic fluorite crystals with polysynthetic growths on the faces and asymmetrically beveled edges, transparent and colorless. They are accompanied by bright and well-defined chalcopyrite crystals, along with complex and transparent honey-colored crystals of sphalerite. With galena and quartz. Highly prized for their rarity.