Whether you’re buying a timeless engagement ring or treating yourself to a sparkling heirloom, understanding the 4Cs of diamonds—Cut, Colour, Clarity, and Carat is essential. These four factors are globally recognised standards that influence a diamond’s beauty, quality, and value. At McGowans Jewellers, our passion lies in helping you find a diamond that’s as unique as your story, with expert advice rooted in over 80 years of experience.

Let’s take a fresh look at what the 4Cs mean for you today.

Cut

The cut of a diamond is arguably the most influential of the 4Cs when it comes to how a stone sparkles. It refers not just to shapes such as round, oval or emerald, but to how well the diamond’s facets interact with light.

A well-cut diamond will dazzle with fire and brilliance, reflecting light beautifully. On the other hand, a poorly cut diamond, even with excellent colour or clarity, can appear dull.

There are three general cut grades:

• Shallow Cut – Light escapes through the sides, reducing brilliance.
• Ideal/Excellent Cut – Precision-crafted to reflect light from every angle. This is the cut that truly brings a diamond to life.
• Deep Cut – Light is lost through the bottom, making the diamond look smaller and darker.

At McGowans, we often find that vintage and antique diamonds, cut by hand in eras before lasers and computers, hold a unique charm and character not found in modern stones. Their sparkle may be softer, but their story is richer.

 

Colour

Diamonds are graded from D (colourless) to Z (light yellow or brown). Colourless diamonds are the rarest and sought-after, but near-colourless stones (G–J) can offer exceptional value with barely any visible difference.

• D–F: Colourless – icy white, rare, and highly sought after.
• G–J: Near Colourless – an excellent balance of beauty and affordability.
• K–Z: Noticeable warmth or tint – sometimes used deliberately for a vintage look.

We often see customers fall in love with diamonds that carry a hint of warmth, especially when set in antique or yellow gold settings. A little colour can enhance a stone’s character.

Clarity

Clarity refers to the presence of inclusions and blemishes. These are nature’s fingerprints and are part of what makes every diamond one of a kind.

The clarity scale runs from Flawless (FL) to Included (I1–I3):

• FL/IF: Flawless or Internally Flawless – incredibly rare and valuable.
• VS1–VS2 / SI1–SI2: Slight inclusions – often invisible to the naked eye.
• I1–I3: Visible inclusions – may affect brilliance but also reduce cost.

Many vintage diamonds will have slight inclusions due to their age and cutting style. Rather than seeing them as flaws, we see them as part of the stone’s journey, a natural beauty mark that tells a story.

Carat

Often misunderstood, carat refers to a diamond’s weight, not just its size. One carat equals approximately 0.2 grams. Larger diamonds are rarer and more valuable, but two stones of equal carat weight can appear very different depending on the cut and shape.

For example, a 1.00ct diamond with an ideal cut can look bigger and brighter than a 1.20ct diamond with a deep cut.

When helping choose diamonds, we always encourage balancing carat weight with cut and proportion. A beautifully cut half-carat diamond can shine just as bright as a heavier one.

Finding Your Perfect Diamond at McGowans

Whether you’re drawn to the old-world charm of an antique stone or the sleek elegance of a modern cut, the 4Cs are your guide. At McGowans Jewellers, we believe that your perfect diamond is the one that captures your heart and suits your personal style.

Visit us in-store or explore our collection online. Our expert team is always available to answer questions, guide your choices, and assist you in selecting a gemstone that will last a lifetime.

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