Opal-CT (variety lussatite) after fossil (Helix ramondi)

Les Rois Mine, Mur-sur-Allier, Pont-du-Château, Clermont-Ferrand District, Puy-de-Dôme Department, Auvergne-Rhône-Alpes  France

Specimen size: 2.4 × 1.6 × 1.4 cm = 0.94” × 0.63” × 0.55”