Watch a video of this specimen by following the Vimeo link below: https://vimeo.com/1168557530/b40462e0f2 Here is an interesting specimen featuring high contrast calcite crystals and balls nested in a geode of dark basalt. On this specimen, different crystal "stages" can be observed, from the single crystal (saddle shape) to the combination of multiple joined crystals that in the end form a ball. A fine specimen from Curebourse, located in the ancient lava flows of the Monts Dore volcanoes. Ex coll. Bac. Jean-Pierre Bac was a highly active regional field prospector in the departments of Cantal, Aveyron, and Lot from the 1970s through the 2010s. He became a specialist of Curebourse and Enguialès, having developed a close relationship with the family who owned the latter mine. Several specimens from his Curebourse collection were illustrated and published in Le Règne Minéral (1999, issue 29). He also made several remarkable and unusual discoveries in a quarry near Miécaze. Another part of his collection consisted of carefully selected international specimens acquired from French mineral dealers during that period.