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What does the 4 Cs of diamond quality mean?

Bespoke made oval diamond cluster ringAll diamonds are awarded a monetary value according to points scored when measured against the 4 Cs of diamond quality.

This is a conversation we often have with clients who come to us seeking a diamond ring, bracelet, pendant, brooch or earrings, whether custom-made by us for them, or selected from our range of European jewellery designers.

So, what are the 4 Cs of diamond quality?

The 4 Cs are:  Clarity, Cut, Colour and Carat weight.  Together these combine to deliver a 5th C – Cost.

Establishing a uniform way in which to quantify the value of a diamond didn’t happen until the middle of the 20th century, which is really quite recent in the history of diamond.

Now, the 4Cs of Diamond Quality is the method used worldwide for measuring the quality of any diamond, antique or new, anywhere in the world.   This is massively important, as it means that anybody who wishes to purchase a diamond is able to know exactly what they are purchasing, and receive a certificate of proof.

bespoke custom made diamond engagement ringFirst, let’s take a look at the meaning of CLARITY

Clarity, in formal terms, means ‘the absence of inclusions or blemishes.’  Diamonds, as you no doubt already know, are formed by the application of immense pressure and heat to carbon deposits deep below the surface of the earth.  In any natural process, perfection is rare.  Inclusions are tiny fissures or splits in the molecular make-up of the internal part of the stone, while blemishes are marks found on the outside of the stone.

Diamonds are evaluated according to the number, size, nature and position of any blemishes or inclusions and how great an effect they have on the way the stone looks to the naked eye.  No diamond is ever 100% pure, but the closer it gets, the higher it scores.

The Gemological Institure of America Diamond Clarity Scale (the globally accepted scale) has six categories, divided into a total of 11 grades.

Starting at the bottom, we have:

6: Included (I1, I2, and I3) Inclusions are obvious under 10x magnification which may affect transparency and brilliance.

5: Slightly Included (SI1 and SI2) Inclusions are noticeable under 10x magnification

4: Very Slightly Included (VS1 and VS2) Inclusions are observed with effort under 10x magnification, but can be characterized as minor

3: Very, Very Slightly Included (VVS1 and VVS2) Inclusions so slight they are difficult for a skilled grader to see under 10x magnification

2: Internally Flawless (IF) No inclusions visible under 10x magnification

1: Flawless (FL) No inclusions and no blemishes visible under 10x magnification

In any fine diamond inclusions and blemishes are too tiny to be seen by anyone other than a trained diamond grader. To the naked eye, a VVS2 and an IF diamond will look exactly the same, but the two diamonds are quite different in terms of Clarity quality and this will be reflected in their assigned monetary value – all other Cs being equal, of course.

an original diamond ring design by Christopher Evans4Cs of Diamond Quality: COLOUR

Essentially, when looking at ‘white’ diamonds, what this actually means is lack of colour.  Again, the natural process of diamond formation, the conversion of carbon in one form to another, means that the range of colours produced is enormous, affected by the addition of other minerals or chemicals during the millennia-long process.  A perfectly clear diamond is the rarest type and the closer you get, the higher the grade.

Clarity is graded from D to Z, with D being the purest and Z being the least pure of colour.  Think of D as being as pure and clear as a dewdrop on a leaf, while Z is a splash from a puddle on the pavement.  They’re essentially the same, but we value dew more than grubby drips any day of the week!  It’s important to understand here that we’re not talking at all about ‘fancy coloured diamonds – the rarest pink, yellow, blue or even red stones so sought after.

White emerald cut diamond bespoke engagement ringThe third C is CUT

Diamonds are adored and treasured for their sparkle, for their ability to capture the light and throw splinters of rainbow back out with every tremble of the hand.  When people choose a diamond, they often see the Cut as being no more than the shape.  But, that shape was chosen by a master craftsman as being the best cut to show off the diamond’s ability to sparkle.  It’s a true skill and precision and artistry, and a true understanding of a diamond’s nature, are necessary to create a finished stone that reaches its full potential.

The cut of every diamond is graded in five steps, from Excellent through Very Good, Good, Fair and Poor.  Each grade is a summary of how the cut affects three key measures:

  1. Brightness: Internal and external white light reflected from the stone
  2. Fire: The splintering of white light into all the colours of the rainbow
  3. Scintillation: The amount of sparkle a diamond produces, and the pattern of light and dark areas caused by reflections within the diamond.

And finally, the one we’ve all been waiting for: CARAT

It’s a common belief that the bigger the stone, the greater its value.  Diamonds are measured not in width or depth, but in weight.  A ‘carat’ is equivalent to 200milligrams, and is split into 100 parts, known as ‘points.’  So when your jeweller tells you that your chosen stone weighs in at 0.73c, he or she means that it has 73 points, or is 73% of one carat.  A stone coming in a 2.65 carats has 265 points, etc.

All things being equal (see Clarity, above!) the heavier the stone – the higher the carat weight – the more valuable it is, as large stones are more rare.  However, don’t forget everything detailed above – a diamond’s final value is determined by a combination of all of the 4Cs, not simply the last one.

How to choose your diamond

This is where the skill and experience of your jeweller comes in.   He or she will have an intimate understanding of diamond valuation – or jolly well should.  If you visit a jeweller who seems a little less sure than you feel comfortable with, find a new one!

If you want a big one, you may need to sacrifice colour and clarity to some degree to remain within budget.  If size is less important than sheer sparkle, then ask about the different cuts available.

Whatever you do, don’t just point at the first ring that falls into your budget parameters and leave it at that.

The joy of the four Cs is that it means that you can find a diamond that meets all your requirements, including the fifth!  Go on a journey of discovery and find the perfect stone for you.