The 4 C:s of a diamond

The "4 Cs" of diamonds represent the four main factors that are used to determine the quality and value of a diamond. These are Cut, Colour, Clarity, and Carat Weight. We like to also add 3 extra C:s on this. Diamond Certificate, Choice and Confidence.

Cut

The cut of a diamond is considered by many experts to be the most important of the four Cs because it has the greatest influence on a diamond's sparkle or brilliance. Unlike color and clarity, the cut is the result of human craftsmanship. The cut encompasses the diamond's proportions, symmetry, and polish, affecting how light is captured and reflected within the stone.

Cut Grades

Diamond cut grades range from Ideal and Excellent to Poor and are determined based on the combined effect of these components on the diamond's overall appearance. The grading criteria can vary slightly between different gemological laboratories, but they generally include:

• Ideal: Ideal
• Excellent: Maximizes brilliance and fire, with very efficient light reflection.
• Very Good: Provides strong brilliance and fire, with slight compromises on proportion for a larger diamond.
• Good: Offers a balance between size and quality, reflecting most light that enters.
• Fair: A diamond that reflects a moderate amount of light but may be cut to maximize size rather than beauty.
• Poor: Reflects minimal light, often due to deep or shallow cutting, and lacks brilliance.

A well-cut diamond will display a balance between its brilliance (white light reflections), fire (the dispersion of light into the colors of the spectrum), and scintillation (the sparkle or play of light as the diamond or light source moves). Even a diamond with high color and clarity grades can appear dull if poorly cut, as it won't reflect light effectively.

When choosing a diamond, it's beneficial to prioritize cut quality to ensure maximum brilliance and fire. A high-quality cut can make a diamond appear larger and more sparkling, enhancing its overall beauty and impact. Alexandra Fine Jewellery only uses diamonds of excellent cut or better.

Colour:

Diamonds are graded on a scale from D (colourless) to Z (light colour). The closer a diamond is to being colourless, the higher its value. Most diamonds appear white but can have slight tones of yellow or brown. The differences in colour can be very subtle, yet they affect the diamond's value significantly.

Grading Scale

The Gemological Institute of America (GIA) established a universally accepted standard for grading diamond colour, which ranges from D (colourless) to Z (light yellow or brown). This scale is divided as follows:

• D-F: Colourless. D being the highest grade, representing absolute lack of colour. These diamonds are rare and highly valued.
• G-J: Near colourless. Very slight colour can be detected by an expert gemologist, usually not noticeable to the untrained eye. These diamonds provide excellent value.
• K-M: Faint colour. A slight colour can be seen with the naked eye, especially when compared side by side with higher-grade diamonds.
• N-R: Very light colour. Colour is easier to detect, even without comparison to higher-grade diamonds.
• S-Z: Light colour. A noticeable colour tint, usually yellow or brown, which affects the diamond's sparkle and overall appearance.

The closer a diamond is to colourless, the rarer and more expensive it is. However, the difference between one colour grade and the next can be very subtle and hard to detect without comparison. The setting of a diamond can also affect its perceived colour. For example, a near-colourless diamond might appear colourless when set in white gold or platinum. Conversely, a colourless diamond might show some contrast when set in yellow gold. This is why we use platinum prongs in our yellow gold engagement rings (unless otherwise wished)

Diamond shapes also influence the perception of colour. For example, round brilliant cuts tend to hide colour better than other shapes like emerald or asscher cuts, due to their superior brilliance and fire.

Considerations for Fancy-Coloured Diamonds

While the D-Z colour scale is used for grading white diamonds, it's important to note that diamonds come in a wide variety of colours, including blue, red, pink, green, and yellow, known as fancy-coloured diamonds. These diamonds are graded based on the intensity of their colour, and unlike white diamonds, the more intense the colour, the more valuable the diamond.

Clarity

This refers to the absence of inclusions and blemishes in a diamond. Inclusions are internal imperfections while blemishes are surface imperfections. Clarity is graded from Flawless (no inclusions or blemishes visible under 10x magnification) to Included (inclusions and blemishes are visible to the naked eye). The fewer the imperfections, the rarer and more valuable the diamond.

Grading Scales

The Gemological Institute of America (GIA) developed a detailed system for grading diamond clarity, which has become an industry standard. The scale includes the following categories:

• Flawless (FL): No inclusions or blemishes are visible under 10x magnification.
• Internally Flawless (IF): No inclusions and only insignificant blemishes are visible under 10x magnification.
• Very, Very Slightly Included (VVS1 and VVS2): Inclusions are so slight they are difficult for a skilled grader to see under 10x magnification.
• Very Slightly Included (VS1 and VS2): Inclusions are clearly visible under 10x magnification but can be characterized as minor.
• Slightly Included (SI1 and SI2): Inclusions are noticeable to a skilled grader under 10x magnification.
• Included (I1, I2, and I3): Inclusions are obvious under 10x magnification and may affect transparency and brilliance.

Inclusions and Blemishes

• Inclusions: Internal flaws such as crystals of a foreign material or another diamond crystal, clouds (small inclusions clustered together), feathers (small cracks inside the diamond), and internal graining (irregularities in crystal growth).
• Blemishes: External imperfections like scratches, pits, and chips. These can occur naturally or be caused during the cutting process.

The clarity of a diamond significantly influences its value; the clearer a diamond, the more rare and expensive it is. However, many inclusions and blemishes are too tiny to be seen by anyone other than a trained gemologist using magnification. Therefore, a diamond does not need to be flawless to be beautiful. In fact, inclusions can sometimes be viewed as a diamond's unique fingerprint, making each stone unique.

For practical purposes, diamonds graded SI1 or higher often appear "eye-clean" to the average person, meaning inclusions are not visible without magnification. Diamonds in the VVS and VS categories offer an excellent choice cause they appear clear to the naked

Carat Weight

This measures a diamond's apparent size or weight, with one carat being equivalent to 200 milligrams. Larger diamonds are rarer and more valuable. However, the value of a diamond increases exponentially with its carat weight, meaning a single two-carat diamond will typically be worth more than two one-carat diamonds of the same quality.

Diamond carat weight measures a diamond's apparent size and contributes significantly to its value and price. The term "carat" has its origins in the carob seeds that were used as a standard of weighing precious stones in ancient times. Today, a carat is a metric unit equal to 200 milligrams or 0.2 grams. The carat weight of a diamond is one of the most objective and straightforward characteristics to understand among the 4 Cs (Cut, Color, Clarity, and Carat Weight).

Understanding Carat Weight

• Precision: Diamond weights are measured to the hundred thousandths of a carat and rounded to a hundredth of a carat. For example, a diamond that is marketed as 1 carat could weigh between 0.995 and 1.004 carats.

• Size vs. Weight: It's important to distinguish between the size and the weight of a diamond. Two diamonds can have the same weight but appear different in size due to differences in their cut proportions. A well-cut diamond can appear larger than a poorly cut diamond of the same weight.

• Price Impact: Diamond prices increase with carat weight because larger diamonds are rarer and more desired. However, the price doesn't increase linearly. For example, a 2-carat diamond will typically cost more than twice as much as a 1-carat diamond of the same quality, due to its rarity.