These stones rarely have any other purpose in jewelry but to flank a stone in a three/five stone ring. They are the supporting cast, not the stars. That is why they are called "side stones" and they are likely to come in pairs. Side stones are divided into two major groups - stones that are set north to south (along the finger) and stones that are set east to west (across the finger). A straight baguette is the only stone that falls into both categories. Each shape could be made in one of two faceting styles - step cut or brilliant cut. Some shapes are practically never made in one particular faceting style.

Tapered Step Cut Baguettes

The most common side stones used in engagement rings. Some might argue that a ring with tapered baguettes should not be called a three stone ring; it should be called a solitaire. This is because baguettes are really not an extension of the center stone. They are set on the "cathedral" part of the shank. The use of tapered baguettes is slightly outdated, but is still a classic way to construct a three stone ring. They could be successfully paired with any shape of center stone. These are slightly boring, yet stylish, traditional and understated.

Tapered Brilliant Cut Baguettes

The brilliant cut version of the tapered baguettes is a novelty cut that looks like somebody crushed them with a ring sizer. In huge sizes they might be attractive in earrings but used in a three stone ring they could be used as a benchmark of lack for individual taste.

Straight Baguettes

Elongated rectangular step cuts could be set either north-south or east-west. When set north-south they are commonly staggered on top of each other forming a ladder-like element. This is the only way they could appear in a modern ring. Set any other way they would contribute to creating an Art Deco look. While stunningly beautiful, Art Deco is not for everyone. If you like the look you might want to consider setting them in channel, east-west setting of a long baguette sandwiched between shorter ones, or many other combinations.

Step Cut Tapered Bullets

Bullet diamonds are direct descendants of tapered baguettes. When cut with a point at the bottom (V-cut tip), straight baguettes become straight bullets (which are rarely attractive). V-cut tapered baguette give birth to a tapered bullet. Bullet side stones are frequently unavailable and have to be custom cut. They are more elegant than tapered baguettes. Since they have a point, they allow for a more elegant flow into the shank of the ring. It is easier to secure tapered baguettes because less metal will have to be used which will be buried under the shank. In combination with half-moons or trapezoids, bullets are marvelous in five stone rings.

Step Cut Straight Bullets

Straight bullets create a slightly more antique appearance, they work well with step cuts such as an Asscher or an emerald cut diamond in the center. They are superb in exerting an Art Deco look.

Brilliant Cut Straight Bullets

Brilliant cut bullets are suitable to match any brilliant cut center. They are not as classy as their step cut counterpart and certainly not as elegant as the tapered version.

 Asscher or Emerald Cuts

The emerald cut side stones step in when straight baguettes are not important enough to be on the side of an Asscher or an emerald cut.

 Step Cut Trapezoids

Step cut trapezoids or "traps", as they are commonly called, are a clever modification of a straight baguette. Trapezoid diamonds are tapered on both ends to form a trapeze. This perspective view of straight baguettes allows for a graceful transition from a large center stone to a narrow shank of the ring. They work great with other step cut stones such as an emerald cut or Asscher cut. They are also a nice fit as part of a traps/bullet combination, which is popular in five stone rings. Trapezoid stones work best next to elongated stones with a straighter side. These stones are not preferable next to round or oval stones.

Brilliant Cut Trapezoids

Brilliant cut trapezoids are the same as step cut trapezoids, but are cut with brilliant faceting. There is a very limited use of these next to radiant cut stones and princess cuts. They are rarely set next to round stones.

Shields

Shields are beautiful whether they are step or brilliant cut. They are great transitional stones that could be paired with virtually any center stone. The most elegant ratio is 1:1 but even elongated they are elegant, complimentary, and appropriate companions to the center stone.

Pseudo-Shields

Sometimes oddly shaped stones are improperly called shields. A pseudo-shield stone is essentially a marquise with 1/3 of it clipped off. They should be classified as modified brilliant bullets and should be shamed out of the market. Yes, it's a great idea to reuse marquises with broken tips to re-cut them into these little monsters, but please don't make our Diamond Ambassador® look for them, much less request we mount them into rings!

 Calf's Head

It is easy to see how closely they are related to shields with just one exception: they do not end in a point. Step cut shields might be pretty but they are difficult to blend into a shank. Brilliant cut calf's heads look more like trillions with broken tips.

 Pear Shapes

The pear shaped stone could be a center stone in its own right or it could be a supporting actor in a brilliant play. Pears are breathtakingly elegant when flanking a round brilliant cut stone. A round stone with two pear shapes is one of the most elegant combinations of stones in a three stone ring category.

Ovals or Marquises

Rarely used as side stones, they could be seen in rings with a matching stone in the center. For example, a large oval stone might have two smaller ovals on each side or a large marquise might have two marquises. Ninety-nine percent of the time they are aligned with the center. Older jewelry commonly used bezel set marquise on the top portion of the shank. Today, it's rarely done in fine jewelry but prong-set marquises are a common fixture in cheap "designer"rings"

 Hearts

Heart shaped stones are a poor match in a three stone ring. They fare better next to a rounded stone (oval, marquise, round), or a cabochon. This is the only shape that could transform a pearl into a viable center stone for a three stone ring.

 Radiants

Radiant diamonds will usually pair well with other radiant stones. Princess cut or modern cushion could be used with radiant sides.

Step Cut Chevrons

Chevrons are similar to trapezoids but they have five sides and a pointy back facing the shank. Sometimes they are called "Cadi" - because their outline reminds of the famous Cadilac logo.

Half Moons

There are two varieties - step cut half-moons and (the more common) brilliant cut half moons. The brilliant cut style is pictured on the left. Half moons could be proportioned differently - chubby ones being less elegant and desirable than the slim elongated type. The only reason you might want chubby half-moons is if you want your stone to grow a set of ears. Step cut half-moons are insanely beautiful but extremely rare.

Trillan

This is the least sophisticated side stone option. There was a time when trillions were wildly popular and every other three stone ring was set with them. The real reason for their short lived popularity was the fact that one particularly difficult to cut rough diamond crystal, called mackle, began to be cut as a triangle. Not suitable to cut into anything else, these crystals were commonly cut as trillions. In its early days, the trillion cut was a novelty. Diamond companies began pushing the sale of these stones. Once it became popular, people realized that there are better options for side stones. They are rarely seen today in high-end jewelry but still common in cheaper "commercial" jewelry.Trilliant is one of the brand names of triangular cuts, generically known as trillions. Trielle is another patented triangular brilliant cut diamond with completely straight walls. It is so ugly that it's almost beautiful.

Kites

Kites could be step cuts. However, brilliant cut kite stones are a much more common variety. Some people believe that they are a viable substitute for a shield or a bullet but the truth should be told: they share the last place in the diamond side stones hall of fame (along with trillions to whom they are closely related).

Crescents

Crescent shaped diamonds are usually skinny half moons with the straight side scooped. Laser cut to better conform to the shape of the center stone, they mostly work with colored stones. Most half moons could be used with a rounded center stone without having the scoop. It's a jeweler's job to construct the ring in a way so half moons fit next to the center stone without a gap. It's not necessary to mutilate the stone. As with half moons the best result could be achieved by converting the three stone ring into a five stone ring by extending the crescents with bullets.

Rounds

Round diamond is a king of a three stone ring - it usually presides over the center of the ring. In a role of side stones round diamonds are screaming for attention and this is not good. The general result is the "Mickey Mouse" effect that undermines their beauty. The only stone to tame their insatiable appetite for celebredom is the Big Brother - a round stone that is big and strong enough to put these cheeky buggers into submission. Other than that, you might have a better effect setting your stone in the middle of a pair of binoculars.