the.com/eternity ring

A diamond-encrusted promise that the relationship, unlike the warranty, never expires.

means A ring set with a continuous band of stones (often diamonds) given to symbolize unending love, typically to mark an anniversary or the birth of a child.

from The 'eternity' comes from the ring's design itself: a full circle of identical stones with no beginning or end, unlike a solitaire that sits at one point. The circle-as-eternity symbolism is ancient — rings generally have carried the idea of endlessness since antiquity, simply because a loop has no stopping point. 'Eternity ring' as a jewelry-trade term for this specific all-the-way-round style is a modern commercial coinage, popularized through 20th-century jewelry marketing, though the circular eternity symbolism it leans on is far older.

origin
popularized by De Beers in the 1960s, naturally
design
stones circle the whole band, no gaps, no excuses
symbolism
often given after a first child, not just marriage
etiquette
worn stacked with engagement and wedding rings, never alone
the.com · every word