Every diamond in the world is unique; finding the perfect engagement ring for you is as much a reflection of your character as anything else. The first thing to do is decide what grade of diamond you want; diamond graders grade the characteristics of diamonds according to four main criteria, Colour, Cut, Clarity and Carat, (otherwise known as “The 4 Cs”). Below is a brief explanation of these terms, to better help you make your decision.


Diamond Grading


The whiter a diamond is, the rarer and more valuable it is. The best and rarest diamonds are truly colourless. Most contain traces of yellow of brown. Colour is a result of the composition of the diamond, and it never changes over time. The diamond colour scale runs from D to Z, where D is a pure dazzling white, and Z is a tinted yellow.

The reason colourlessness is most highly valued is that diamonds in these ranges act like prisms, separating white light passing through it into a wide spectrum of colours. The more transparent the diamond, the wider the spectrum of colours. Chemical “impurities” in the diamond will filter out some of the colours which in turn reduces the fire of the diamond.

D colour solitaire diamond ring

Fancy colour diamonds do not follow this rule. These diamonds, in colours such as red, blue, pink or purple,are very rare and very expensive, are actually more valuable for their colour.

Determining the colour grade of a diamond is a skill. You must train your eye to ignore the sparkle of the diamond, and instead look “into” the stone, to see the colour.
Here are a few tips to how to do this;

* Use non direct, natural light. Shop lights will always give a false colour, either better or worse. Direct sunlight makes it extremely difficult to grade colour.
* Try if possible to use Northern light (ie turn to the north). This ensures that the light is totally diffused and there is no direct light entering the stone.
* Use neutral background colours. Standing opposite a red-brick building, for example, may make you think that you are looking at a pink diamond!!! In the same vein, avoid wearing bright or strong colours – a bright tie, shirt or scarf can reflect into the diamond, and tint it slightly.
* Look diagonally into the diamond, focussing your eye about halfway into it. This takes a bit of practise, but soon becomes second nature.
* Use comparison stones. There can be a huge price diference between a D colour and an E colour, for example. If in doubt, compare with known standards.
Ultimately, if you are not sure, ask to see a report (“a diamond certificate”) from a reputable diamond laboratory. The most widely known, and reputable, is the Gemmological Institute of America, but there are many other labs around the world of high standard.


A good cut gives a diamond its brilliance, which is that brightness that seems to come from the very heart of a diamond. The angles and finish of any diamond are what determine its ability to handle light, which leads to brilliance. They also disperse light, which gives a diamond fire.


Skillful cutting is necessary to ensure that the fire and brilliance of the diamond is maximised. The brilliant cut, first used as long ago as 1750, became the standard cut in 1919. Diamonds cut before then tend to have more fire than modern cut diamonds, while modern cut diamonds exhibit more brilliance than antique diamonds.

In a well cut diamond, most light enters through the table and travels to the pavilion where it reflects from one side to the other before reflecting back out of the diamond through the table and to the observer’s eye . If the stone is too deep, light is lost through the sides. If the stone is too shallow, the light that enters through the table reaches the facets and then ‘leaks’ out from the sides or bottom of the diamond rather than reflecting back to the eye. Less light reflected back to the eye means less brilliance.

We carefully check all of our diamonds to ensure that they are cut for maximum beauty, and not for size.

Cut can also refer to the shape of the diamond: the most common shapes are

  • round brilliant; the most popular style of cutting, circular in silhouette, with 58 facets. An
    excellent cut for maximum light return.
  • emerald cut; a square or rectangular cut, with 50 facets (typically). A wider open table highlights the clarity of the diamond, leading many people to describe the emerald cut as being like ice. A popular type of emerald cut is the Asscher cut, developed in 1902, it became popular during the Art Deco period. The Asscher cut is a step cut with square octagonal outline and truncated corners. It was designed by the Asscher Diamond Company; the Asscher family were the family given the responsibility of cutting the Great Star of Africa. True Asschers are quite rare, and possess amazing life.
  • cushion cut; an antique cut, similar to the round brilliant cut in the shape and number of facets, but a higher crown and deeper pavilion give cushions more scintillation than a modern round briliant cut. Sometimes slightly rectangular in shape.
  • pear shape; the pear cut shape is a popular shape that looks like a tear drop. This is a traditional cut which is perfect for pendants, drop earrings and rings. Generally has 57 facets.
  • marquise shape; pointed at both ends, the marquise cut has 56 facets, and ranges from very long and narrow to almond shape. Suits long fingers.
  • princess cut; the top of the diamond is cut in a square shape and the overall shape is similar to that of an inverted pyramid. It has gained in popularity in recent years.

To view different styles of cut, please browse through our pages, otherwise call into the shop where we will be delighted to discuss them with you, and show you examples.


Almost all diamonds contain minute inclusions, or “fingerprints”. The size, position and nature of these inclusions determine the clarity grade of the diamond. The purest diamonds are graded as “Flawless”. The majority of our diamonds are in the Flawless to SI1 range.

One pitfall to avoid when shopping for a diamond engagement ring is the “clarity-enhanced” diamond. This is an artificial process used to “fix” the flaws on an otherwise good stone. Although a clarity-enhanced diamond can look pure, it is intrinsically worth as much as a flawed stone. Furthermore, the durability of the diamond can be greatly compromised.

At Weldons we NEVER sell clarity enhanced diamonds.


Carat is a measurement of weight. One carat equals 0.2 grams. Diamonds of the same weight will differ in value depending on colour, clarity, cut and fluorescence. However, bear in mind that a small diamond of high quality can be more valuable than a large stone of lesser quality.


About one in every three diamonds exhibit Fluorescence, a reaction to UV light caused by atomic impurites in the diamond. Most fluorescence is blue, but sometimes other colours can be seen as well. Fluorescence can reduce the value of a diamond. The purest diamonds will have no fluorescence, or weak fluorescence.


Ethical Diamonds

Diamond Engagement Rings from Weldons have always been purchased from legitimate sources not involved in funding conflict and in compliance with United Nations resolutions. We hereby guarantee that all of our diamonds are conflict free, based on our personal knowledge and/or written guarantees provided by all suppliers of our diamonds.


A diamond report (sometimes called a certificate) is a “fingerprint” of a diamond; it tells you the diamond’s exact measurements and weight, as well as the details of its cut and quality. It precisely points out all the individual characteristics of the stone. Diamond Reports also serve as proof of the diamond’s identity.

It is important that the report comes from a good laboratory; some laboratories are less stringent with their gradings than others. Most of our diamonds come with diamond reports issued by the GIA or HRD, or other reputable international gemmological laboratories. Where an antique setting does not allow for a diamond to be removed from a setting, our in-house gemmologist will issue a grading on it. We have trained with the GIA in diamond grading, and Jimmy and Garret Weldon possess almost 70 years of experience in diamond grading between them.

Care of your Diamond

Diamonds are the hardest substance on earth. They are uniquely resistant to damage by heat or scratching, and can be cut or polished only by another diamond — but an extremely hard blow to the girdle can cause a diamond to chip. By having your diamond set in a relatively protective setting, and remaining conscious of it on your finger, you can keep your diamond intact for a lifetime. Exposure during ordinary wear to perspiration and household chemicals, like chlorine and hairspray, can cause build-up that dulls the surface of a diamond. We suggest periodic cleanings to keep the diamond brilliant and refractive. We also offer free cleaning of any diamond engagement ring we sell; just call into the shop.