What evidence is there for Tolkien's One Ring being based on the Ring of Silvianus?

Question

I recently heard a theory that parts of Tolkien's legendarium and the Lord of the Rings story may have been inspired by the real-life Ring of Silvianus:

As Wheeler consulted with J. R. R. Tolkien on the name of the god invoked in the curse, the ring and curse may have inspired the One Ring in The Hobbit and The Lord of the Rings. [...] It is hypothesised that Wheeler, in his discussion with Tolkien on the name Nodens on the curse tablet, would also have discussed the ring at The Vyne, with which he was familiar. It is thought that other aspects of the archaeology of the Lydney area, including an Iron Age fort known as Dwarf's Hill, may have influenced Tolkien's writings.

The only sources cited by Wikipedia for these claims are articles in a few UK newspapers (the Daily Express, the Guardian, and the Independent). None of these are particularly reliable sources. But the fact that the Tolkien Society takes it seriously enough to help set up a Tolkien-themed "Ring Room" at Vyne is interesting, and lends the theory more weight.

What evidence is there for the idea that Tolkien based his One Ring on the Ring of Silvianus?

As far as I knew, Tolkien took most of his ideas from Germanic mythology, so a real-life inspiration like this is interesting. Evidence could come either from the text itself or from any kind of extratextual material - other writings set in Middle-Earth, Tolkien's letters or notes, ... Even a reference to an academic paper about this, rather than just newspaper articles, would be appreciated.

Answer 1

If there was any inspiration, it was likely very minor. The only thing this ring seem to have in common with the One Ring is the curse, and that Tolkien could easily have gotten from elsewhere.

The most obvious inspiration for the rings of power is Andvaranaut from the Völsung cycle: a magical ring which gave great riches to the owner, but at the ultimate cost of their destruction. It was first owned by the dwarf Andvari and taken from him by Loki to give to Hreidmar, king of the dwarfs, as part of a ransom; Andvari cursed the ring. This fits well with the seven rings given by Sauron to the kings of the dwarves, as well as the One ring. Andavaranut is responsible for Fafnir's transformation into a dragon, and, likely, for the continued misfortunes of Sigurd and the Nibelungen.

Considering Tolkien's general approach to creating his legends, my opinion is that this is a likely point from where the general concept of the rings of power was developed. Some would instead argue that Tolkien was primarily inspired by Wagner's ring cycle (e.g. here), but that does not seem strictly necessary. Some influence is likely, but not to the point that LoTR should be seen as a variation on Wagner rather than the original. Let's not forget that the War of the Ring is a small ripple in the aftermath of more cataclysmic events; the One Ring was originally not the major focal point it would be when LoTR was published.

There is also the Ring of Gyges, a story told by Plato in The Republic of a ring that can turn it's wearer invisible, which destroys the original owner's morality, but not through any inherent corruption but by removing the restraints placed on him by other's observation. Even if Tolkien appears to never have alluded to this in any text, it is not an unlikely influence.

In my opinion, The Lord of the Rings could very well have been written exactly as it was even if the Ring of Silvanus had never been unearthed.