The name of such a ring is usually "Talisman." Here is another of Browning's jewels, one of the last poems written shortly before his death.

It is entitled "Summum Bonum,"-- signifying "the highest good." The subject is a kiss; we may understand that the first betrothal kiss is the mark of affection described.

When the promise of marriage has been made, that promise is sealed or confirmed by the first kiss.

But this refers only to the refined classes of society.

Among the English people proper, especially the country folk, kissing the girls is only a form of showing mere good will, and has no serious meaning at all.
All the breath and the bloom of the year in the bag of one bee: All the wonder and wealth of the mine in the heart of one gem: In the core of one pearl all the shade and the shine of the sea: Breath and bloom, shade and shine,--wonder, wealth, and--how far above them-- Truth, that's brighter than gem, Trust, that's purer than pearl,-- Brightest truth, purest trust in the universe--all were for me In the kiss of one girl.
There is in this a suggestion of Ben Jonson, who uses almost exactly the same simile without any moral significance.