What is better, 4 or 6 prongs?

In a four-prong setting, a single sheared or badly bent prong puts the diamond at immediate risk, because three remaining prongs cannot grip a round girdle evenly enough to stop it pivoting. In a six-prong setting, losing one prong still leaves five distributed around the stone, which is usually enough to hold it until the next inspection. The practical impact is small for office and studio routines where the ring is rarely knocked, and significant for healthcare, trades and parenting young children. Buyers who travel often, where a jeweller is not always nearby, choose six prongs for the same redundancy reason.

Four prongs cover less of the crown, so more light reaches the table and the stone reads brighter in everyday photos. The outline-solid of a round diamond also looks cleaner with four prongs at the cardinal points than with six at the clock positions, which is why most modern solitaires are built four. Six prongs cover roughly half again as much surface, soften the round outline-solid slightly and can make a one carat stone read closer to its true size rather than a touch larger. Platinum prongs are a useful middle ground: four-prong security gets close to six-prong because platinum bends and thins more slowly than gold.