The 4C of Diamonds: Colour, Clarity, Cut, and Carat

When choosing a diamond, whether for an engagement ring, a special gift, or as an heirloom, you will often hear experts referring to the 4Cs. These four characteristics (Colour, Clarity, Cut, Carat) are the universally accepted standards for evaluating the quality and beauty of a diamond, whether natural or lab grown. Understanding each of them helps you make a confident decision and get the most sparkle for your budget.

 

Colour

Colour in diamonds refers not to fancy coloured diamonds (blues, pinks, etc.), but rather to the subtle presence of body colour (usually yellow or brown) in what would ideally be a near‑colourless or colourless stone. The standard colour scale runs from D (completely colourless) down through the alphabet (E, F, G, etc.). The less trace colour a diamond shows, the higher its grade, and typically, the higher its price.

In practice, slight degrees of colour are often imperceptible to the naked eye, especially once the stone is mounted in a ring. The choice of metal (white gold, platinum, yellow gold, or rose gold) and the setting style can influence how ‘white’ your diamond looks. In many cases, balancing colour grade with other Cs gives you a better overall return on investment than chasing the absolute top colour grade.

 

Clarity

Clarity describes how clean and clear a diamond is. That is, whether internal inclusions (tiny natural imperfections) or external blemishes are present. The clarity grading scale ranges from Flawless (no inclusions visible at 10× magnification) down to I (which stands for Included), where inclusions may be visible to the naked eye.

A stone with fewer inclusions tends to be rarer and more expensive. But it’s important to remember that not every 'flaw' is visible or distracting. Diamonds with a grade of VS1 or above, which is the grade that we use as standard here at Lily Arkwright, appear beautifully clean to most people, especially when set. Unless you’re inspecting with a loupe, many inclusions simply won’t matter in everyday wear.

An included diamond and an Internally Flawless diamond 

 

Cut

If colour and clarity are about the internal and material qualities of a diamond, cut is about how the diamond interacts with light. A well-cut diamond catches light, reflects it internally, and returns it to the viewer, creating that signature sparkle and fire. Even a high‑colour, high‑clarity diamond can look dull if its cut is poor. A diamond's cut can also refer to its general shape, which you can read more about in our handy guide to all different diamond shapes. 

Cut has many facets (no pun intended). Proportions, symmetry, polish, and how angles are aligned all play a role. Many gem labs also award cut grades (Excellent, Very Good, Good, etc.). When you're comparing diamonds, many experts advise prioritising cut even above colour or clarity, because it's the cut that truly brings life to the stone.

If you’d like more detail on how diamonds are evaluated and certified (and how that certificate helps guide your decision), check out our post on IGI vs GIA: Diamond Certification Explained.

 

Carat

Carat simply refers to the weight of the diamond (1 carat = 0.2 grams). Two diamonds of the same carat weight might look different in size depending on their proportions, shape, and cut quality.

Choosing the ‘right’ carat weight is often about balancing visual presence with budget. Sometimes you get better value just under the ‘magic number’ (for instance, just under 1.00 ct rather than exactly). If you’re wondering which carat diamond is best for your ring, you may find our post on Which Carat Diamond is the Best? helpful.

Also, in the context of engagement rings and why diamond remains the classic choice, you can read more about why diamonds are used in engagement rings, and dive into the history, symbolism, and enduring appeal which give diamonds their special place in romantic jewellery.

credit: GIA

 

Ready to Start Shopping?

At Lily Arkwright, we believe knowledge empowers beautiful decisions. Whether you’re in the early stages of exploring diamonds or ready to pick your stone, keep the 4Cs in mind.

Our dedicated consultancy team are on hand if you’d like help comparing stones, understanding certificates, or guiding you toward the diamond that balances brilliance, quality, and value.

Now that you’re familiar with the 4Cs, it’s time to start exploring! Whether you’re drawn to the timeless beauty of natural diamonds or the ethical innovation of lab-grown diamonds, Lily Arkwright offers a hand-picked selection of exceptional engagement rings for every style and budget.

Explore our full collections and find the diamond to tell your love story!