Cut is the most influential of the Four Cs, shaping how a diamond captures and reflects light. Defined by proportion, balance and polish, it directly impacts a stone’s brightness and overall beauty. At SARAH & SEBASTIAN, every diamond is carefully selected for exceptional cut quality. Round diamonds are always Triple Excellent, while all other shapes are graded Excellent to Very Good, ensuring light, not size alone, defines its impact.

When a stone is cut with imprecise proportions or alignment, light escapes through the sides or base, resulting in a muted appearance regardless of colour or clarity. A well-cut diamond, in contrast, reflects and refracts light back through the crown, creating brightness, fire and scintillation. For this reason, SARAH & SEBASTIAN prioritises cut quality in every diamond selection, ensuring each stone is proportioned to maximise light return rather than relying on carat weight alone.

Clarity refers to the natural characteristics formed as a diamond develops under extreme heat and pressure deep within the Earth.

These internal inclusions and surface features are assessed under magnification, based on their size, number and placement. While a Flawless diamond shows no visible characteristics under 10× magnification, it’s often the balance of clarity and overall beauty that matters most.

We individually select our diamonds ensuring that inclusions are not immediately visible to the eye and do not compromise the stone’s appearance.

Carat is a measure of weight, not visual size, with one carat equal to 0.2 grams.

Two diamonds of the same carat weight can appear very different depending on how they are cut, proportioned and finished.

Rather than prioritising weight alone, SARAH & SEBASTIAN diamonds are chosen for balance, symmetry and beauty. We believe a diamond’s presence should feel considered and harmonious and it’s this balance (not size in isolation) that gives a diamond its lasting appeal.

Diamond colour refers to the natural presence of tint within a white diamond. It is graded on an industry-standard scale from D to Z, with D representing the most colourless and rare stones. The closer a diamond is to colourless, the more exceptional its beauty and value.

At SARAH & SEBASTIAN, we select only natural diamonds graded between D and G, chosen for their refined appearance and clear, luminous presence once set.

Colour is the second most important of the Four Cs, as it directly influences a diamond’s overall appearance. Diamonds with a low grade can show a noticeable yellow tinge, particularly in natural light, which can affect how white and brilliant a stone appears.

At SARAH & SEBASTIAN, each diamond is individually assessed, and stones with strong or visually disruptive fluorescence are not selected, ensuring your SARAH & SEBASTIAN diamond maintains clarity and brightness.