What are the four Cs of diamonds? Understanding diamond quality and grading

To become an informed engagement ring shopper, take a few minutes to learn the 4 Cs in diamonds.


Diamond universal language

The diamond quality is defined by each of the 4 Cs of diamonds: Cut, colour, clarity and carat. The grades a diamond carries in these four areas give a clear idea of the diamond quality, beauty and by extension the right price you should be willing to pay.


The cut of a diamond is associated with its shape. There are several different cuts available. The traditional diamond shape is round brilliant, it has the greatest brilliance of all shapes. Other shapes include: The emerald, princess, oval, marquise, cushion, trilliant, radiant, pear, and heart shaped cut and all come down to personal taste.

The cut is the only diamond component not influenced by nature, it relies on skilled craftsman to create the perfect angles, symmetry, and proportion of the diamond.

Easily the most important of the Four Cs, an accurately proportioned stone will maximise the light it reflects to make it sparkle. In the jewellery trade this is referred to as fire and brilliance. Fire is the rainbow flashes of light reflected from within the stone. Brilliance refers to the diamond’s brightness.


The diamond colour is the second most important of the 4 Cs because it affects the colour grade of the stone appearance.

Diamonds are graded on a colour scale ranging from D through to Z. Diamond prices decline or increase in alphabetical order. For instance, a diamond with D colour grade is more expensive than a diamond with G colour grade.

The highest quality diamonds are colourless. The rarest and highest quality with a pure icy look, D-F grade diamonds are absolutely colourless diamond and demands the highest price.

Near colourless diamonds, G-H and I-J are great value for quality and have no discernible colours.

Faint colour diamonds are ranging from K-Z and are budget friendly and pair beautifully with yellow gold. On the other hand, diamonds with a very vibrant hue are highly prized by jewellery lovers and are often the most valuable. These coloured diamonds are known as ‘fancies’ and come in all shades of the rainbow from canary yellow, a rosy red and tangerine orange all the way to hot pink, lime green and sky blue. There are even black diamonds which are often mistaken for dark sapphires given their similar hues.

Choice of colour comes down to personal taste.

As a general recommendation, review each diamond closely and ask for assistance. This is the best way to ensure you are not paying for a feature that will go unnoticed.


The clarity of a diamond is indicative of the stone’s appearance internally and evaluates the diamond’s purity by measures it based on the presence of blemishes and inclusions (Nature’s birthmarks/internal flaws).

The fewer the inclusions, the greater the clarity and value. Using a 10-power magnification glass will help spot the imperfections as they are sometimes not visible to the naked eye. Diamond with inclusions visible to the naked eye are graded I1to I3. It is very rare for a diamond not to have at least some inclusions; however, most will not be visible to the naked eye.

Clarity is graded as followed

  • FL (Flawless)
  • IF (Internally flawless)
  • VVS1 (Very, very slightly included 1)
  • VVS2 (Very, very slightly included 2)
  • SI1 (Slightly included 1)
  • SI2 (Slightly included 2)
  • I1 (Inclusions 1)
  • I2 (Inclusions 2)
  • I3 (Inclusions 3)


A carat is defined as one fifth of a gram (200 milligrams) or (0.2 grams). Carats can also be measured in points; 100 points is equal to a full carat. Diamonds that are under one carat will often be referred to as “pointers”.

Carat refers to the measuring system used to determine the weight and size of a diamond. Naturally, the larger the carat, the more expensive the diamond. However, carat weight does not determine the diamond’s value by itself. Two diamonds of the same weight can have very different value because of the cut, clarity and colour are taken into consideration.

However, it is important to note that the bigger a diamond’s carat is, the more expensive it will be.

Recommendations: When it comes to diamonds, bigger is not always better as you also must factor in the quality of the stone. To save money it is recommended to choose a slightly below the carat mark diamond and focus on a balance of the 4Cs to make a smart purchase.

Get the humm app
and buy now pay later.