Prong

Vertical posts coming up from a base beneath the stone and notched to form a seat that the girdle of the stone sit into. The tips of the prongs are burnished slightly over the girdle, creating inward and downward tension on the stone from opposing directions.

4 or six prong? This is a common question and there is no "correct" answer. It is really a matter of personal choice and a tradeoff. Four prongs are sufficient to secure a stone properly. Smaller stones set with six prongs tend to look overwhelmed by the metal. Therefore, many professionals feel that six prong settings be reserved for larger stones of a carat or more.

Bezel

A thin rim of metal completely encircles the stone, affording a very high degree of security and protection. More of the surface area of the stone is covered using this method, and to some degree the stone is harder to clean by non professional means. A bezel creates a very "clean" look and tends to be more wearable in the sense that there no prongs to catch on things.

Channel

Invisible setting

A modern technique that utilizes specially grooved princess cuts that are capable of being secured from underneath. The effect is a solid surface of diamond with no prongs or other hardware visible.

Pavé

A technique for creating a surface encrusted with small round diamonds. The diamonds sit into a drill hole are secured by tiny beads of metal that are pushed up against the girdle of the stones. The diamonds are separated only by the width of these tiny beads.

Rim

Similar to a bezel in that the stone is secured with a thin rim of metal. But the stone is set directly into the metal via a drill hole and the rim is graved from the metal onto the stone. The effect is that the stone appears to be pressed into the metal.