Can a stone fall out of a bezel setting?

A well-made bezel almost never loses a stone in normal wear, and the rare failures fall into two categories. The first is poor workmanship at the time of setting: a rim that was not properly tightened over the girdle, or a base seat that was cut slightly too deep, so the stone has a hair of movement that grinds metal away over years. The second is decades of cumulative wear: the rim slowly thins from contact with hard surfaces, until at some point it can be deformed by a single hard knock. Direct impact can also dent the rim enough to lift it off the stone in one event.

A bezel needs a check every 12 to 24 months, roughly half as often as a prong setting. The jeweller looks at the rim under magnification for hairline cracks, lifted edges and any movement when the stone is gently pressed, and polishes out cosmetic wear at the same time. Bezel repairs are also rarer in absolute terms: industry data suggests bezel repair frequency runs roughly an order of magnitude lower than prong maintenance over equivalent periods. That makes total lifetime maintenance cost the lowest of any mainstream engagement setting.