Classic 4 prong solitaire with low knife shank. Note the setting basket extended to the finger.	Modern Optima Solitaire with high shank providing space for 1.5mm thick wedding band behind the setting.

The truth about the unsuitability of the classic solitaire and the likes to be paired with normal band is seldom disclosed in the shops when potential deal is being forged. Then, when it is time for the wedding band, there have to be alterations made, either to the back of the setting or to the wedding ring, both resulting in compromising the integrity of the pieces and their appearance.

There is nothing wrong with the good old classic solitaire diamond ring. It is still very popular and a very good choice, in case it is going to be alone on the finger. When intended to be a part of a set however there is far better engagement ring options providing the necessary space behind the setting. The intention of wearing a wedding ring next to the engagement ring should be considered when choosing the style of the ring and discussed with your jeweller. Even the most complicated shapes of rings can be fitted with suitable band but in such case it is a good idea to order them together

If you already have a classic solitaire or prefer low collet that extends to the finger, using a wave band can solve the fitting  problem	Even a complicated halo swirl can be fitted with a band which more or less runs along the shape of the ring

The Profile of the shank is the way it looks from the side.  For the classic solitaire engagement ring it could be knife, strait or tapered.

Knife shank	Strait shank	Tapered shank

The knife shank serves the purpose of the Classic solitaire best. It shows less metal than the other two while it has bulked metal for strength where it is most needed – at the back. The knife shank if properly proportioned, allows the designer to achieve very slim, almost invisible ring making the diamond look like it is suspended on the finger, without compromise in strength and durability.

Strait shank is the one that best fits with wedding bands, although the other two are also fine if the height and the setting are suitably chosen. It is often combined with a set of two bands (one on each side) and it is the best choice for diamond studded shank (see below).

Tapered shank is employed when the visibility is not an issue and the shank is intended to play part in the overall design.  It is the place to implement detail like engraving if required. The back of this type of shank, being the narrowest part, must have minimum thickness of at least 1.5mm to ensure strength and longevity.

The detail on the shank of a solitaire engagement ring is predominantly a row small diamonds set on its visible upper part. The studded part seldom extends towards the bottom half of the shank, since the back of the ring is highly exposed to abrasion and the metal keeping the diamonds in place is soon worn off, while on the other hand the very hard diamonds tend to scratch everything one touches. The types of setting usually used to set the diamonds on the shank are pave, shared prong (claw) and channel. Pave and shared prong appear quite similar on first sight and the main difference is  the border cut around the pave area which is missing when shared prong is employed

Pave studded shank. Note the bordered pave area. The border could be thin or substantial, but it is always there.	Shared prong studded shank. The girdles of the diamonds extend almost to the edge of the metal. (no border)	Channel set shank. The wide borders provide sufficient metal for secure locking of the diamonds in place.

Although similar in appearance the two types of setting are fundamentally different. In pave the stones are first deeply set into the metal, then beads of metal are pushed over and finally the surrounding metal is removed. The shared prong setting is what it is called – prong set diamonds positioned slightly above the base metal. The shared prong type is showing very little metal and allows very delicate, diamond intense shank. The diameter of the diamonds here is almost equal to the width of the shank. On the other hand the borders of the pave set shank keeps the edges of the diamonds less exposed preventing them from scratching neighbouring rings. The channel set is less popular since it requires substantial thickness on the side in order to maintain the rigidity of the shank with a channel in the middle. It is recommended only for platinum rings

The Collet

The diamond in a classic solitaire setting is set in prongs. The number of prongs is usually 4 or 6 with occasional use of 8 prong setting for really large stones. There is great diversity of styles but for the purposes of this article we will look at the three most popular currently.

The collet of the solitaire engagement ring, as with its shank, should not be obtrusive and showing too much metal is considered bad. Compromising the safety of the setting for the sake of the look  on the other hand is far worst. Even the most stylish collet is useless if it is not secure.  Loosing even a small diamond is rather painful and when it comes to a solitaire diamond ring the stones are more on the large side.  A good jewellery designer should maintain fine balance between safety and aesthetics with safety being the first priority. There is common perception that the 6 prong setting is safer than the 4 prong one which is not entirely true. The main factor determining the safety of a prong setting is the balance between the lever of the prong (the distance from the edge of the diamond to the first support) and the thickness of the prong.  First support is usually provided by a link or detail joining the prongs together under edge (girdle) of the diamond. The longer the lever – the thicker should be the prong. It might sound a bit complicated but the sketches below are quite illustrative.

The very short prong lever (less than a millimetre) of this classic solitaire collet results in an extremely sturdy and very secure holding of the diamond.  If made in platinum the thickness of the prongs of such setting can be reduced by 25-30% without compromising on the safety.	In this 4 prong protea collet the lever is much longer. To ensure relevant strength more thickness is added. Note the added bulk to the prong right after the setting edge (girdle) of the diamond. The balance is maintained and this setting is as strong as the one on the left.

As with the chain, the collet is as strong as its weakest prong. If the lever is long and the thickness of the prong not sufficient, the number of prongs will not help. Four prong collets are more popular, since they show less metal and are friendlier to bands when worn as a set.  Most solitaire diamond collets are available both in four and six prong version. On the pictures below is 4 and 6 prong interpretation of the protea collet applied to different shanks. The 4 prong collet is coupled with low knife shank and it finishes to a point almost next to the finger. This setting can accommodate thin half round band behind the collet.  If the six prong version is used here the middle prong will be lifting the band. Six prong collet is therefore coupled with high shank providing space for even studded band behind the collet

Four prong protea collet coupled with low knife shank. The collet extends almost to the finger.	Six prong protea collet coupled with high knife shank providing space for thick studded band.

Obviously there are many more designs steaming from the solitaire engagement ring concept and they are more or less possible to combine in order to achieve the right setting.  Viewing the shank and the collet of a solitaire engagement ring setting as interchangeable elements and thus combining different collets and shanks creates opportunity to align our aesthetic view to practicality.