Draupnir

Draupnir is essentially a myth. Never seen or encountered it is rumoured to lie under Notre Dame Cathedral in Parisius and it's discovery would lead to the wearer to rise in power through wealth becoming the ultimate leader in the Frankish Empire.

Supposedly created by two Svartalfheim Dwarven brothers, called Brokkr & Eitn. One of the three gifts given along with Mjolnir and Gullinbursti, and was originally as part of a bet. This bet was made by Loki who said to Brokkr, that he & Eitn couldn't make better magical gear than those made by the Sons of Ivadli.

They won with the creation of Mjolnir.

With Draupnir, the ring was given to Odin who then went on to place it on the funeral pyre of Baldr. After that it vanished. Exactly where it is is unknown but the myth persists about under Notre Dame Cathedral. The myth states that the one wearing it will have 8 duplicates drop from it every 9 days.