Created by the Gemological Institute of America (GIA), the 4Cs denote the four most important characteristics of a diamond: cut, colour, clarity and carat. These key attributes are graded to help you choose the highest quality diamond within your budget. Diamonds do not have to be perfect across all four areas and there is no "correct" set of diamond specs. A matter of personal preference: the grading system helps you to determine what is important to you.

“Every diamond is one of a kind, and that’s what makes finding yours so special. The 4Cs are a helpful guide, but what really matters is your personal preferences. We know just what to look for in a stone and we’ll help you navigate the options to find a diamond that truly resonates with you.”

— Ayesha, Sales Team

Carat is a measurement of the diamond’s weight. It measures the weight of the stone as opposed to the size, so it is worth looking at the dimensions of the stone alongside the carat weight when choosing your diamond.

This is where the shape of the stone plays a crucial role. Typically, elongated shapes such as ovals and marquise create the illusion of a larger diamond, as do rings with a narrow, delicate band and slender prongs. 

Our recommendation: when choosing carat weight, focus on what feels right for you. Consider how the diamond’s shape and setting can influence its perceived size, and remember to balance carat weight alongside other key factors (such as cut, clarity, and colour) to ensure a beautiful diamond overall.

When we talk about the colour of a diamond, we refer to its natural hue—or the absence of it. On the GIA scale, diamonds are graded from D (colourless) to Z (light yellow or brown), with diamonds closer to D being prized for their bright, classic appearance.

Diamonds with more intense colours, such as vibrant yellows, are classified as fancy-coloured diamonds. Fancy-coloured diamonds fall outside the D-Z scale and are graded based on the intensity and distribution of their colour. These rare and unique stones come in a wide range of hues, including yellow, pink, blue, green, orange, and even red, offering endless possibilities for those seeking something truly one of a kind.

Our recommendation: we advise opting for stones graded between D to H, as they are considered 'white,' striking a balance between colour quality and visual appeal.

Clarity measures the presence of internal imperfections (known as ‘inclusions’) and external imperfections (called ‘blemishes’), which can affect a diamond’s transparency and brilliance.

Clarity is graded using the GIA Diamond Clarity Scale, which ranges from Flawless (FL)—with no visible inclusions or blemishes under 10x magnification—to Included (I1, I2, and I3), where imperfections are more noticeable.

Our recommendation: we recommend selecting diamonds with clarity grades ranging from Flawless (FL) to Slightly Included (SI1), as these stones offer a beautiful balance between quality and value while maintaining a visually clean appearance to the naked eye.

A diamond’s cut is one of the most important factors influencing its brilliance and sparkle, as it determines how effectively the stone’s facets reflect and refract light. Unlike shape—which refers to the diamond’s form, such as round, oval, or pear—the cut grade evaluates the quality of the diamond's proportions, symmetry, and polish.

The Gemological Institute of America (GIA) assigns cut grades exclusively to round brilliant diamonds, categorising them as Excellent, Very Good, Good, Fair, or Poor. Formal cut grades are not given to fancy shapes like ovals or pears due to the complexity of evaluating their unique facet arrangements.

At Grew & Co, we place a strong emphasis on sourcing diamonds with exceptional cut quality, as this characteristic truly brings a diamond to life. A well-cut diamond not only enhances its brilliance but can also make the stone appear larger and more luminous, ensuring for a radiant piece.

Our recommendation: we strongly recommend diamonds with 'Excellent' to 'Very Good' cuts, as their exceptional shape enhances the overall visual appeal of the stone.

Colour: D–H

Diamonds within this range offer a bright, white appearance, with D being completely colourless.

Clarity: Flawless to Slightly Included

Most inclusions in this range are microscopic and have little to no impact on a diamond’s beauty.

Cut: Excellent to Very Good

A well-cut diamond enhances brilliance, ensuring maximum light return.

While these guidelines help ensure quality, diamond selection is ultimately personal. Whether you prioritise size, clarity, or unique characteristics, our team is here to guide you. Visit our Sydney or Melbourne showrooms or get in touch online for expert advice.