Diamonds & The 4C's
Here we explain a little about what makes each diamond unique. A diamond’s quality and value is assessed and graded based on what is regarded as the four most important characteristics – Carat, Colour, Clarity and Cut, known as the 4C’s. Devised in the mid twentieth century by GIA, it has become the internationally recognised system universally adopted throughout the jewellery industry globally.
DIAMOND CARAT WEIGHT
A diamond’s weight is measured in Carats (ct). One metric carat is equal to 0.2g. Each carat is divided into 100 points and so weight is expressed to the hundredth decimal place, for example 0.25ct. Diamond weight greater than one carat would be expressed as carats and decimals, for example 1.25ct. Generally speaking, the greater a diamond’s carat weight, the larger it’s size.
A diamond’s colour, or lack of colour is measured on an alphabetical scale ranging from D to Z, D being colourless, Z being tinted yellow. Coloured diamonds greater than Z are described as ‘fancy’ and are categorised according to the intensity or saturation of the colour. Totally colourless diamonds or ‘fancy’ colours such as yellow, orange, blue, pink, are the most valuable. Most colour distinctions are so subtle they are invisible to the untrained eye and must be assessed using master stones in a controlled environment.
Diamond clarity refers to the lack of inclusions or blemishes within a stone. Internal characteristics ‘inclusions’ occur during formation under tremendous heat and pressure deep inside the earth. Determining diamond clarity involves establishing the type, size and nature of inclusions within a stone to establish how they impact on the overall appearance. The GIA diamond clarity scale is divided into 6 categories with 11 specific grades.
FLAWLESS (FL) No inclusions or blemished visible under 10x magnification
INTERNALLY FLAWLESS (IF) No inclusions visible under 10x magnification
VERY VERY SLIGHTLY INLCUDED (VVS1 & VVS2) – Inclusions so slight they are difficult for a skilled grader to see under 10x magnification.
VERY SLIGHTLY INCLUDED (VS1 & VS2) – Inclusions are minor and not immediately obvious under 10x magnification.
SLIGHTLY INCLUDED (SI1 & SI2) – Inclusions are noticeable under 10x magnification.
INCLUDED (I1, I2, I3) – Inclusions are obvious under 10x magnification and may be visible to the naked eye. They may also impact the transparency and brilliance of a diamond. Large and/ or numerous inclusions may be present.
The cut of a diamond refers to the way the light interacts and travels through a stone. This translates to how a diamonds shines and its sparkle factor. The depth of a cut as well as the number of facets a diamond has all impact the way a diamond will reflect the light.