4C's of Diamond

Before the mid-twentieth century, there was no consensus on how diamonds should be evaluated for their quality. However, the Gemological Institute of America (GIA) established the first globally accepted standard for describing diamonds, the 4Cs of Diamond Quality.

This standard assesses a diamond’s colour, clarity, cut, and carat weight. Today, the 4C’s remain the universally recognised method for evaluating the quality of any diamond, regardless of its origin.

The Diamond 4C’s had a significant impact for two critical reasons.

Firstly, it allowed a universal language to communicate diamond quality transcending geographical boundaries.

Secondly, arguably more importantly, it gave diamond customers the confidence to know precisely what they were purchasing. This development was a game-changer in the diamond industry.

Colour

Diamond colour is distinct from the spectral colours that flash when a diamond is in motion; it refers to the stone’s inherent body colour.

Typically, diamonds have slight tinges of yellow, brown, or grey due to natural trace amounts of nitrogen during the diamond’s formation beneath the Earth’s crust. A less colourful diamond is considered rare and, therefore, more valuable.

Clarity

Clarity of a diamond refers to how clean and clear it is, taking into account any microscopic natural characteristics that may have been trapped inside or on the diamond during its formation.

These characteristics can appear inside the diamond as inclusions or on the surface as blemishes. Inclusions may be foreign material crystals or structural imperfections like tiny cracks known as feathers, which may appear whitish or cloudy.

Cut

The cut of a diamond isn’t about its shape, but rather the balance of proportion, symmetry, and polish achieved by the diamond cutter. How well a diamond is cut determines its overall beauty.

A well-cut diamond can significantly enhance its ability to reflect and refract light. Diamond cutters have studied how light travels through diamond crystals, enabling them to establish specific proportions and angles that bring out a diamond’s internal brilliance and showcase it in the best light possible.

Carat

Carat (ct.) is a distinctive unit of weight measurement used solely for weighing diamonds and gemstones. Despite this, carat weight is often mistakenly equated with visual size. The weight of a gemstone will appear differently depending on its shape and type.

For instance, a 1.00 ct. round diamond will measure approximately 6.5mm, while a 1.00 ct. round sapphire will measure around 6.0mm. This difference is caused by the differing densities of various gemstones.