Settings: the six that hold and the two that do not

A setting has one job and a second job. The first is to hold the stone. The second is to let light into it. Every design in the category is a compromise between the two, and the compromises fail in predictable ways after predictable intervals.

The settings, by how they hold

• Bezel: a rim of metal surrounding the stone entirely. The most secure setting there is, protects the girdle from knocks, and admits the least light from the sides. Excellent for anyone who uses their hands.
• Half bezel or semi bezel: metal on two sides, open at the others. A sensible compromise, and it protects the two directions a ring is most often knocked.
• Six prong: the classic solitaire. Two redundant prongs, so losing one is an inconvenience rather than a disaster. Slightly more metal over the stone than four.
• Four prong: shows more of the stone and has no redundancy. One failed prong on a four prong setting means a stone that will move and then go.
• Flush or gypsy: stone sunk into the metal with the table at surface level. Extremely secure, popular for the stones in a signet or a band, admits very little light.
• Pave and channel: many small stones held by shared beads or a rail. Secure per stone and impossible to ignore when one goes, because the gap is obvious. Expect to lose one occasionally over decades.
• Tension: the stone held by the spring pressure of the band. Spectacular, and it makes resizing difficult to impossible and concentrates all the risk in a single mechanical property.
• Illusion and cluster settings with fine metal work: pretty and fragile, and they trap dirt where you cannot reach it.

How a prong actually fails

Metal at the tip of a prong is thin by design, because a thick prong hides the stone. Every contact with a surface removes a little of it. Over years the tip goes from a rounded claw to a flattened, thinned shape that no longer curls over the crown of the stone, and the stone begins to rock. Once it rocks it wears its own seat, which accelerates everything.

The warning signs are all available without a jeweller. Push the stone gently with a fingertip: it should not move at all. Run the ring across a piece of silk or a fine knit: a lifted prong catches. Listen to the ring near your ear and tap it: a loose stone rattles faintly.

A stone that moves under a fingernail has weeks, not years. Everybody who has lost one describes the same sound they had been ignoring.

Retipping, which is routine and cheap

A jeweller adds metal to the worn tips and reshapes them. Expect 20 to 60 per prong, an hour of work, and a ring that is good for another decade. Done at the first sign of thinning it is trivial. Done after a stone has been lost it is a different conversation with an insurer.

The maintenance schedule that prevents almost all losses is one inspection a year, which most jewellers do free because they would rather sell the retip than deal with the aftermath. Put it in the calendar next to the boiler service.

Matching the setting to the life

Anyone whose hands are in bags, gym equipment, gardening or a keyboard for eight hours wants a low profile and a bezel or a six prong, not a high four prong solitaire. A high setting catches, and every catch is a small blow to the prongs.

The other consideration is the stone. Diamond is extremely hard and reasonably tough, and can be set almost any way. Emerald is brittle and included and wants protection at the corners, which is why the emerald cut exists at all. Opal, tanzanite and pearl are soft enough that a bezel is close to compulsory in a ring.

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