Diamond ring and scattered diamonds on a dark surface with a black box.

The 4Cs of Diamonds – Complete Guide

Choosing a diamond is an emotional and meaningful journey. Many couples who visit our boutique often tell us the same thing: “We’re overwhelmed by all the information online — we just want to understand what truly matters.”
That’s why the 4Cs were created — Cut, Colour, Clarity and Carat — a universal grading system developed to help you understand a diamond’s beauty and value.

At Cerrone, our master jewellers have spent over five decades hand-selecting diamonds. Every stone we choose is examined carefully so you can feel confident and informed when finding the perfect piece.

Illustrations of various diamond cut shapes on a white background

COMMON DIAMOND SHAPES

DIAMOND CUT – The Key to Brilliance

Diamond cut is the single most important factor influencing a diamond’s sparkle. While many people assume cut refers to shape, it actually describes how precisely the diamond’s facets are proportioned and polished.

A perfectly cut diamond reflects light internally from facet to facet before returning it through the top of the stone. This creates the brilliance, fire and scintillation that make diamonds so captivating.

Poorly cut diamonds allow light to escape through the sides or base, resulting in a dull appearance even if the diamond has excellent colour and clarity.

At Cerrone, diamonds are selected for their exceptional cut proportions to maximise light performance and brilliance.

Diamond cut grades typically range from:

Excellent
Very Good
Good
Fair
Poor

TIP: Diamonds with Excellent or Very Good cut grades deliver the greatest sparkle and visual impact.

A well-cut diamond reflects and refracts light beautifully.

Poor cut reduces brilliance, even if other grades are excellent.

Diagram of diamond clarity grades with geometric representations on a white background

Internal Grading

DIAMOND CLARITY – Nature’s Fingerprint

Clarity evaluates the presence of internal inclusions or external blemishes formed during a diamond’s natural creation deep within the earth.

Most inclusions are microscopic and invisible without magnification. Clarity grades include:

  • FL – Flawless
  • IF – Internally Flawless
  • VVS1 / VVS2 – Very Very Slightly Included
  • VS1 / VS2 – Very Slightly Included
  • SI1 / SI2 – Slightly Included

Many diamonds in the VS or SI range appear perfectly clean to the naked eye while offering excellent value.

( More clarity information from GIA: https://4cs.gia.edu/en-us/diamond-clarity/ )

TIP: Most inclusions are invisible to the naked eye.

At Cerrone, each diamond is inspected for the position, visibility and
structural impact of inclusions — not just the grade on paper.

Colorless to light yellow diamond color grading chart on a white background

DIAMOND COLOUR – The Absence of Colour

Diamond colour measures how colourless a diamond appears. The less colour present, the rarer and more valuable the diamond.

The diamond colour scale established by the Gemological Institute of America ranges from D to Z:

  • D–F: Colourless (extremely rare)
  • G–J: Near colourless (excellent value)
  • K–M: Faint colour
  • N–Z: Noticeable colour

Many beautifully bright diamonds fall within the G–H range, offering exceptional value while still appearing colourless to the eye.

(Learn more about diamond colour grading at the GIA: https://www.gia.edu/diamond-color)

TIP: Metal choice affects how colour appears — yellow gold can make diamonds look whiter, while platinum and white gold show the true colour.

  • Choose a grade that suits your eye, style and budget. Many customers find G–I diamonds beautifully balanced.
Diagram showing diamond size and weight measurements on a white background

DIAMOND CARAT - Weight & Presence

Carat refers to a diamond’s weight, not necessarily its visual size. One carat equals 200 milligrams.

Larger diamonds are rarer, which increases their value. However, two diamonds of the same carat weight can appear very different depending on cut proportions and shape.

For example:

  • A well-cut diamond may appear larger and more brilliant than a heavier diamond with poor proportions.
  • Different shapes — such as oval or marquise — can create the illusion of greater size.

Our consultants help you balance carat weight with cut, colour and clarity to achieve the most beautiful result.

LEARN MORE ABOUT ADVANCED DIAMOND QUALITIES