Bellecroix calcite on a french gogotte

Calcite of Belle-Croix is a French deposit unique in the world. These rhombohedral crystals were formed in the soil of the Paris area (Fontainebleau) during the periods of glaciation of the quaternary. This block seems to be 40,000 years old (which is very young for a mineral! Calcite precipitated into the contact zone of the frozen permafrostl over 20 meters thick and the thermal flux from the center of the earth that was warmer. These crystals with a rhombohedral shape (a cube whose sides are diamonds), are here hung on a Gogotte of Fontainebleau: A super French mineral , as these 2 formations are not found elsewhere. Except in most mineralogical museums in the world...