The 5 Principles

When buying diamonds, the most common advice given is usually called the 4 C’s (Cut, Carat, Clarity & Colour).

It’s not that the 4 C’s are without significance, but there are other factors that should be considered. We recommend considering the following, which we call the 5 principles. They are as follows:

  • Make
  • Cut
  • Fluorescence
  • Colour
  • Clarity

By following the 5 principles, Diamond Centre Wales ensures that the diamond you select has the highest level of brilliance possible for its cut, shape and price.


The make of the diamond refers to it’s symmetrical perfection, particularly the proportions of the crown. It is the single greatest factor in the beauty of a diamond.

Often people get confused between the “shape” of the diamond and the “make”.

Diamond shape is just that – round, princess, marquise, pear, oval, heart etc (click here to see some of our favourite shapes).

A good make diamond will allow the highest level of light to be reflected back up through the facet lines and facet points in the crown of the diamond. This creates the sparkle that makes us gasp with delight.

The make of a diamond affects the beauty of the stone far more than colour or clarity.


To achieve a very fine make, you have to have an excellent cut.

Cut refers to the symmetry, proportioning and polishing of a diamond.

With poor symmetry and proportioning, light will be lost before it makes it required journey back up through the facet lines and points in the crown, reducing the level of “fire” that it emits.

With poor polish you can have a lifeless diamond.

Only with perfect symmetry, ideal proportions & excellent smooth facets, will the transformation occur from rough stone to a dazzling diamond.

A good tip is to ask about the origin of the diamond (and not just for ethical sourcing reasons). If the diamond has been cut in Belgium (Antwerp) or Israel for example, it is likely to have been cut using the highest level of modern technology for diamond cutting.


Fluorescence is a measure of the opaqueness within the stone. Basically the diamond emits a soft coloured glow when in ultra-vilolet light. This gives the diamond an oily or milky appearance in light and will therefore not sparkle as much, decreasing its value.

Many years ago jewelers used to refer to diamonds with a high fluorescence level as “blue-white” diamonds, inferring that this was in some way a superior diamond. It was of course an inferior diamond.

You should always look for “nil fluorescence” in the diamond you are purchasing.


At Diamond Centre Wales we are committed to creating the best jewellery possible for your budget.

It’s quite natural to want the best. As such it’s common to look at the highest value on the colour chart – which for Diamond colour would be “D” and desire that.

The truth is, to the naked human eye, its almost impossible to tell the difference between a diamond with the colour grade of D and a diamond with a G.

From the point of view of keeping a sensible budget, we’d recommend going for a diamond that appears “ice white” to the naked human eye. This is usually a G.

There is nothing wrong with wanting a D, but it will cost more and your eyes, and the people who look upon your diamond, won’t be able to tell the difference.


Clarity refers to degree to which a diamond is free of interior or exterior blemishes and inclusions. The size and position of inclusions affects the value of a stone according to whether or not they interfere with the passage of light through the diamond.

There are four key considerations with regards to clarity and inclusions

Size – How big are they?

Number – How many are there?

Position – Are they in a place that could be covered by the setting or in a highly visible position?

Nature – is the inclusion internal or external? If the flaw is internal then it excludes the diamond from being categorized as flawless or internally flawless. If the inclusion is external then the diamond is automatically flawless.

For most people trying to get the most out of their budget, we’d recommend a diamond that is “eye clean”. Eye clean can be anything from VS2 to SI1 depending on your eye sight.


Carat is the unit of mass used to measure diamonds.

As with all precious stones, the weight and the size of a diamond is expressed in carats. Diamonds were traditionally weighed against the seeds of the carob tree until the system was standardized and one carat was fixed at 200 milligrams. One carat is divided into 100 points. So for example a diamond of 150 points weighs 1.5 carats.

The size of a diamond often tends to be high on the shopping criteria of many customers. Bigger is better right? Well only if size is all you are concerned about. Overall, you want a sparkling diamond that makes people gasp. Depending on your budget, you may have to compromise Carat weight for some of the other factors in the 5 principles.