Diamonds are the hardest natural minerals on earth, coveted worldwide for their crystallised structure and ability to refract light – that’s how they achieve such a brilliant shine.

In 1947, diamond miners De Beers coined the infamous term, ‘a diamond is forever’. Society’s love affair with diamonds is relatively recent, but they were first discovered thousands of years ago. Going back even further, the process of formation is takes hundreds of millions of years.

It’s no wonder we often gift diamonds to capture life’s precious moments and memories – they have a fascinating history of their own.

You probably know that diamonds tend to be weighed in carats (ct). However, they can also be classified in points.

  • 100 points is equivalent to 1ct.
  • 50 ct is also referred to as 50 points.
  • TDW refers to the total diamond weight that is present in a ring (all diamonds added together).

We have more details about carats below.

When it comes to diamonds, you just need to consider the universal standards known as the 4Cs.

These are:

  • Colour
  • Clarity
  • Cut
  • Carat

A brief explanation is below.



Diamonds are often coloured on a scale of clear to yellow. Typically, the highest-quality diamonds are totally colourless, while those which are lower in quality may have a yellow or brown tint.

To the untrained eye, these differences may appear subtle. Thankfully, there is a universal scale created by the Gemological Institute of America (GIA). They are the largest and most respected source of gemological knowledge in the world.

The scale starts at D (colourless) and goes all the way to Z (light yellow or brown in colour). Between D and Z, there are numerous diamond colour grades, ranging from near colourless to slightly yellow.



Diamond clarity relates to the diamond’s visual characteristics. When considering clarity, we look at internal defects known as inclusions and external blemishes.

Diamonds have quite the journey before making it into your jewellery; they are formed from carbon as a result of incredible pressure and heat being applied in the earth. As you might imagine, it’s almost impossible to find a perfectly pure diamond.

To establish a diamond’s clarity, we use the GIA Clarity Scale, a qualitative scale that grades the visual appearance of each diamond. The fewer inclusions and blemishes the diamond has, the better the clarity grade it will receive.

The clarity can significantly impact a diamond’s value; however, imperfections generally can’t be recognised by the naked eye. Experts use magnification to distinguish the correct grade. Most diamonds fall into the SI1 – SI2 category.



Diamonds come in lots of different shapes, such as round, heart, marquise, oval and pear. However, when we talk about the cut, we are not actually talking about the shape, because this is a narrower characteristic referring only to the profile of the stone as viewed from above.

Instead, we refer to how well its facets interact with light. The cut determines how the diamond will reflect light back to the eye of the observer – this is also called light performance. Many different factors are associated with light performance, from a diamond’s proportions to the artistry and craftmanship involved.

Light performance is extremely important for maximising the brilliance and sparkle of a diamond. The cut of a diamond is generally regarded as far more important in showing off a diamond’s “fire” than the clarity of the stone. In this sense, “fire” refers to the scattering of light into the colours of the rainbow.

The GIA Cut Scale is the most complex metric of the 4Cs of diamonds. Diamonds are graded as follows:

  • Excellent
  • Very good
  • Good
  • Fair
  • Poor

When grading a diamond, experts consider its weight relative to its diameter, its girdle thickness (which affects its durability), the symmetry of its facet arrangement, and the quality of polish on those facets.

 Diamond carat weight and size are not the same as it all depends upon the cut. Carats refer to how much a diamond weighs, whereas size is all about the dimensions. A poorly graded diamond has a poor weight ratio. It may appear darker, and because of its proportions, may be far smaller than its carat grading might imply.


A diamond may have a shallow pavilion, and a wider Girdle/Table which creates the look of a larger diamond, however the best dimensions are supposed to be a crown about 1/3 the size of the pavilion with a very narrow cutlet to avoid this being visible through the top of the diamond.



Carat (ct) is a weight equal to 200 mg. The current definition, sometimes known as the metric carat, was adopted in 1907 at the Fourth General Conference on Weights and Measures, and soon afterwards in most countries around the world. Diamonds are weighed in carats (ct).  However, they can also be classified in points.

  • 100 points is equivalent to 1ct. (1 point = 2mg)
  • 50 ct is also referred to 50 points.
  • TDW refers to the total diamond weight that is present in a ring (all diamonds added together).