What the 4Cs Really Mean, and Which Are Most Important

Ever wonder why two diamonds of the same size are priced so differently? It all comes down to the four factors that determine the quality (and price) of a diamond: carat, clarity, colour, and cut.

Which of these four C’s are most important? In the diamond market, each is equally important with certain specific aspects falling in and out of favour depending on market demand; these can affect pricing slightly from time to time. The most important factor is whichever one is most important to YOU. Read through our detailed discussion of each of the 4Cs below to get an impression of what matters most to you. Then make an ordered list of which ‘C’ you feel is most important to least important, and stick to it when shopping!

1. Carat

Carat is by far the most commonly understood factor of the price of a diamond. A carat is a measure of a diamond's weight, not its size. Common weights for the centre stone of a ring are 0.25 carat, 0.5 carats, 0.75 carats, and the quintessential full 1.0 carat diamond ring. A heavier diamond doesn't necessarily mean a better diamond, but it always means a more expensive one!

Be aware of some tricky terminology. If you see a ring advertised as 1.0 total carats (or TCW, which stands for total carat weight), this means that the ring is composed of a number of smaller diamonds that altogether total one carat. However, a single diamond that weighs one carat is worth FAR more than several smaller ones that add up to one carat.

2. Clarity

Clarity refers to how free a diamond is from imperfections. Imperfections in a diamond are called inclusions, which tend to be bits of other material that formed inside the diamond. Inclusions impede the light rays from bouncing around inside the diamond, which makes the diamond appear darker overall. An "ideal" diamond is one with no inclusions (referred to as flawless), although some people believe that inclusions give a diamond character. It's all up to the beholder, really, but diamonds with fewer inclusions cost much more because they're rarer.

Clarity is based on the following grade scale, from best to worst:

Flawless F Extremely rare and expensive
Internally Flawless IF Rare and expensive
Very, Very Slightly Included VVS1 VVS2
Investment grade diamonds
Very Slightly Included VS1 VS2
Very high quality, common in high-end jewellery
Slightly Included SI1 SI2
Good quality, common in designer jewellery and boutique stores
Included I1 I2 I3
Low quality, common in discount jewellery and chain stores

A significant portion of the cost of a diamond is based on its clarity. You can easily add thousands of dollars to the cost by selecting a VS2 clarity diamond over a SI1 clarity, for example. Likewise, if the diamond is of I clarity, don't get tricked into spending a lot of money on it.

At K. Amani Fine Jeweller, we price all of our custom diamond engagement rings using diamonds from SI2 to VS2 clarity, unless requested otherwise by the customer. We hand-pick all of our diamonds to ensure they are the best possible quality for a given clarity.

3. Colour

As light bounces around inside the diamond, it can take on a tinted colour, similar to the way light separates through a prism. Ideally, a diamond should exhibit a white colour, or be colourless. However, depending on the quality of the cut of the diamond or the type of inclusions within it, this can tint the diamond toward yellow or brown. The more yellow or brown the diamond, the worse its colour rating.

Colour is based on a letter scale, with D being colourless and Z being obviously yellow. Yes, the colour scale STARTS with D, so if a salesperson tells you a diamond is of A, B, or C colour, turn around and walk out of the store; they either don't know what they're talking about, or they're lying to you.

Excellent colour is between D-F, but this is expensive. Very acceptable colour is from F-I, and most jewellers create their stock within this range. The yellow tint present in this range is so minor as to be almost invisible to the naked eye.

At K. Amani Fine Jeweller, we price all of our custom diamond engagement rings using colour between F-G, unless requested otherwise by the customer.

4. Cut

The cut is essentially a diamond's shape, and how well it has been cut to the "ideal" standard. Common shapes include round brilliant, princess, oval, and emerald. The type of cut plays a big factor in the amount of sparkle, or fire, the diamond gives off. A round brilliant cut has much more fire than an emerald cut, for example. Some cuts are more expensive than others, but which cut is most expensive fluctuates with the market.

The cut of a diamond is also rated based on how well the cut conforms to the ideal standard set for it. This includes things like number of facets, symmetry, and angles. These factors are extremely important as they greatly affect the amount of light refracted by the diamond. A single misaligned facet can cause a diamond to look 'dead' and 'dark', thus ruining an otherwise beautiful diamond. When looking at the quality of a cut on a grading certificate, the grading will range from excellent to poor. Buy a diamond only if its cut quality is excellent or very good. Do not buy a diamond if its cut quality is only good,fair, or poor. These lower gradings can affect something as crucial as the overall shape, like a princess cut that's meant to be a square but is really rectangular! Beware any grading that doesn't follow the convention discussed above - e.g.: a grading that uses terms like sensational or magnificent. These terms are merely marketing hype and are highly misleading.

A retail or discount jeweller is likely to stock only cuts that are the most likely to sell, which are round brilliant and princess. A boutique or high-end jeweller will have a greater selection of cuts, especially including emerald, pear, and marquise. Some of these cuts are associated with more vintage designs.

At K. Amani Fine Jeweller, we are happy to modify any of our ring designs to accommodate a specific diamond cut that you prefer. We also custom-create ring designs specifically designed to showcase your chosen diamond's shape.