When F. P. Journe decided to switch to an entirely 18K pink gold movement – an industry first - the 99 final pieces of the five Journe calibres in production were coated in ruthenium, an element known for its extreme hardness and chemical inertia. The same process was applied to the dials as well, and thus the "Ruthenium Series" were born.

The five watches that are part of the collection, beyond this model, are the Tourbillon Souverain, the Chronomètre à Résonance, the Octa Calendrier and the Octa Chronograph. All of these models are ruthenium coated counterparts to their brass peers. The present Octa Réserve de Marche Jour et Nuit model has however a different story to tell. It is the only model from the Ruthenium Series which is unique, without a brass movement counterpart. The cal. 1300, which powers it, is also present in the Octa Réserve de Marche, but without the day/night indicator: a detail present exclusively on the Ruthenium Series. It is unknown why Mr. Journe decided to upgrade exclusively cal. 1300, leaving the other four untouched. What is certain is the fact that this is the only F.P. Journe piece that is singular to the Ruthenium Series, therefore enormously amplifying the importance and collectability of this watch.

Enhancing its desirability, it is preserved in excellent condition with its original accessories, and numbered 58 of the limited edition of 99 pieces.