A lifetime opportunity does not come along every day. 

The idea started with a name coincidence. I was looking for an extinct volcano in central France. The highest peak is named Puy de Sancy, and in the same web search, there was also a link to one of the most famous diamonds the Nicolas de Harlay, de Sancy diamond.

A derivative to Sancy is Sancus. From the wiki:

Sancus was also the god who protected oaths of marriage, hospitality, law, commerce, and contracts in particular. Some forms of swearings were used in his name and honour at the moment of the signing of contracts and other important civil acts. Some words (like "sanctity" and "sanction" - for the case of disrespect of pacts) have their etymology in the name of this god, whose name is connected with sancire "to hallow" (hence sanctus, "hallowed").

Therefore, all the loose ends are tied up, this time using two pixels: the rocks of the wedding rings.