From l’Engarvin, take the path for the “Col St-Michel”, then follow « l’Eguisse », to the South (Many urchin fossils in the Turonian).

The deposit took place in a little graben past the Eocene, and is related to the tectonic activity : hydrothermal origin.

Deposit exploited from 1902 to 1911, and from 1923 to 1930.

100 meters of trench, and 240 meters of galleries, with 3 pits and 2 descenderies.

All in two parts, one hundred meters distant.

On the other side of the l’Eguisse ravine an experimental factory was built, and a cable brought the ore from the South side to the other.

In the Cenomanian marls : realgar crystals (and sometimes orpiment) to 1 cm long in calcite veins. It’s a typical stockwerk. Some beautiful calcite geodes can be found in the limestones over the marls.

Revue Minéraux et Fossiles, 1978

Revue Le Cristallier Suisse, février 1989