Renowned for their beauty and dazzling appearance, diamonds have mystified people for centuries. Throughout history, diamonds have been thought to possess special powers to cast away the devil, be able to cure diseases and even hailed as tears from the Gods – to name just a few!

How are diamonds formed?

Diamonds are naturally crated deep within the Earth through intense pressure and heat. Formed by pressurised carbon atoms, diamonds possess an incredibly strong atomic bond due to the carbon formation.

It’s this particular carbon-atom bonding that makes diamonds so unique. Without it, we would have a completely different mineral known as graphite – the material used in pencils.

Once the diamond is formed, it can exist for up to millions of years below the Earth’s surface. In fact, diamonds found now are thought to have originally formed between 20 billion and 100 million years ago. Some of the world’s major sources of diamonds are in Brazil, South Africa, Namibia, Australia and Canada.

Why are diamonds considered so valuable?

Whilst diamonds are formed by nature, finding ones that are of gem quality is incredibly rare – this is what makes them so valuable.

Plenty of diamonds are mined, but the vast majority are brown to yellow in colour with a lot of inclusions. Such diamonds are therefore not considered gem quality, and are typically used for industrial purposes. Due to their incredibly hard, strong formation, they make excellent materials for cutting.

Only a very small percentage of mined diamonds are considered gem quality, and it’s these diamonds that are eventually cut, polished and made into dazzling jewellery. In fact, whilst there are plenty of diamond cutting centres across the globe, the oldest is here in Amsterdam – hence the name City of Diamonds.

The Value Characteristics of a Diamond

As diamonds are naturally formed, every single one is unique – with some being rarer than others dependent on their characteristics.

Consequently, the rarer a diamond is the higher its value. So, if you’re looking to purchase a truly authentic, valuable diamond, it’s essential you know the exact characteristics to look for.

Typically, there are 4 primary characteristics that determine the true value of a diamond – the 4 C’s.

Clarity

Clarity is the term used to describe the number and size of inclusions found within a diamond. In simpler terms, clarity determines how ‘clean and clear’ the diamond is.

Virtually all diamonds will contain minuscule traces of non-crystallized carbon and growth marks. However, such inclusions aren’t visible to the naked eye and require strong magnification to be seen, so won’t typically interfere with a diamond’s overall appearance.

But certain larger inclusions will inevitably interfere with the way the diamond disperses light, therefore altering its brilliance and rendering it imperfect. Due to this, the fewer the inclusions a diamond has, the rarer and more valuable it is.

To grade the clarity of a diamond, a 10x magnification is used to inspect the diamonds for inclusions. After inspections one of the following grade is assigned:

FL or IF: A diamond that shown no inclusions and external blemishes under a 10x magnifications will be graded as Flawless. If there are only some polish marks visible (an external blemishes) the diamond will be graded as Internal Flawless. Diamonds that are graded FL or IF are considered extremely rare.

VVS1 or VVS2: Very Very Slightly Included. Under a 10x magnification inclusions are very difficult to see for a trained grader, the diamond will usually only has minute pinpoints. VVS graded diamonds are very rare.

VS1 or VS2: Very Slightly Inclusions. The diamond will have minor inclusions and are still difficult to see for the untrained eye.

SI1 or SI2 Slightly Included. Inclusions will be easy to see with 10x magnification. Most of the time the inclusions will not be visible with the unaided eye. SI1 and SI2 graded diamonds are the best when it is about price/quality.

I1, I2, I3 Included. Diamonds with an I grading have inclusions that are obvious when viewed under 10x magnification. The inclusions are even visible to the trained naked eye.

Colour

Whilst diamonds are typically associated with being colourless, many mined diamonds actually have subtle brown or yellow tones. These can often be detected when comparing side by side.

As diamonds are formed via intense pressure and heat, it’s relatively common for other elements to be naturally incorporated into their structure – this explains any variances in colour a diamond may possess.

When assessing colour, a ‘perfect’ diamond will be completely colourless. These are considered the most valuable and rare, as the most common diamonds will have slight tints of yellow or brown.

However, contrary to this, there are some diamonds that come out of the ground with vivid, well-defined colours. These diamonds are sometimes called "fancy" diamonds. Such colours can include red, blue, pink, green and bright yellow. Diamonds with such vivid, bold colours as opposed to simple yellow/brown hues are considered extremely rare and valuable – perhaps even more than those that are colourless.

The most common scale for grading the colour of "white" diamonds is the alphabetical scale (developed by the Gemological Institute of America, G.I.A.) from D to Z, with D being colourless and Z being light yellow. Other scale that are still used is the Scandinavian standard, the Scan D.N.

GIA D E F G H I J K L M N O P Q R S-Z

Scan D. N. River Top Wesselton Wesselton Top Chrystal Chrystal Top Cape Cape Colourless Near Colourless Faint Yellow Very Light Yellow Light Yellow

Diamonds that are graded D/E or river are colourless and are very rare. Although the presence of colour makes a diamond less rare and valuable, some diamonds come out of the ground in vivid "fancy" colours - well defined reds, blues, pinks, greens, and bright yellows. These are highly prized and extremely rare.

Cut

The cut of a diamond is how well the diamond is faceted. Whilst all three of the above characteristics (clarity, colour and carat) are defined by nature, the cut of a diamond is solely in the hands of craftsmen.

The way a diamond is cut is what provides its unique brilliance and sparkle, as the primary goal is to allow as much light to enter and reflect from the diamond as possible. So, if a diamond is cut with expert precision and skill, dazzling shine and brightness will be the outcome.

In fact, the cut of a diamond is so important that two diamonds with the exact same clarity and colour can look completely different dependent on how they’ve been cut. If one cut is excellent and the other is poor, the difference will be glaringly obvious.

Whilst a diamond cutter will want to cut a diamond with perfect proportions, this sometimes simply isn’t possible. As they’re formed by nature, the original form of a diamond is often far from ideal – leaving the cutter with an important choice before their work begins.

If a diamond craftsman opts to cut a larger diamond, brilliance is likely to be compromised. But if they choose the brightest, most ‘perfect’ looking diamond to cut instead, size will be sacrificed. Each option is valuable in its own right and, regardless of the expert skill of the diamond cutter, ideal proportions aren’t always possible to achieve.

Taking all of this into account, a large diamond that is cut in perfect proportion is perhaps the most rare & valuable diamond of all.

Carat

Often shorted to ct, a carat is the measurement of a diamond’s weight and size. A carat is the equivalent of 0.2g, and a diamond’s worth is highly likely to increase with its weight. The larger and heavier the diamond, the more expensive per carat it will be.

In terms of measurement, one carat is divided into 100 ‘points’. So, a diamond with 25 points will be described as 0.25 carats, or a quarter of a carat.

However, ‘carat’ is not to be confused with ‘karat’. Carat refers to a stone’s weight and size, whereas karat refers to the fineness of gold.

Value

A diamond is a product that is formed by nature through a process of millions of years. Since nature produces more yellow/brownish diamonds that are small with a lot of inclusions, a E / VVS diamond has higher price than a I / SI diamond. When consider other C’s constant, the value of diamond tends to go up exponentially when a “C” grade goes up with one notch. The graph below shows the relationship between the grading of the C’s and the value. It is impossible however to say that the colour is more important than the clarity or that the carat weight of a diamond is the most important factor. Each of the 4-C’s has is own contribution to the beauty of diamond. In the end you are the only one to determine which of the 4-C’s is more important.