Calcite with sand inclusions

Bellecroix, Fontainebleau, Seine-et-Marne, Île-de-France  France

Specimen size: 16.5 × 11 × 8.5 cm = 6.50” × 4.33” × 3.35”
Main crystal size: 2.5 × 1.7 cm = 0.98” × 0.67”