The 4Cs of Diamond Quality
Every diamond is as unique as our fingerprints and up until the middle of the twentieth century, there was no agreed upon standard by which diamonds could be judged.
The Gemological Institute of America (GIA) created the first, and now globally accepted standard for describing diamonds in the 1940s; the 4Cs – Colour, Clarity, Cut and Carat Weight. Today this is a universal method for assessing the quality of any diamond, anywhere in the world.
Cut. The diamond Cut is perhaps the most important aspect of a diamond quality that impacts a diamond’s beauty. The diamond cut refers to the quality of the angles, proportions, facets, and finishing details, how well a diamond’s facets interact with light. The cut of a diamond is directly related to its overall sparkle and beauty.
Colour. The diamond Colour evaluation is the second most important aspect to focus on and is based on the absence of colour; how colourless the diamond is. Diamond Colour is graded in terms of how white or colourless a diamond is. GIA grading for diamond colour is from D to Z, with D being the most colourless, and Z containing noticeable brown or yellow tint. Pricing of diamonds usually reflects the grade, the most critical aspect with colour is to determine if it appears colourless in relation to its setting.
Clarity. The diamond Clarity is the third most important and evaluates how clean a diamond is from both inclusions and blemishes. Natural diamonds can be several billions of years old and the solid form of the element carbon, they are formed deep within the Earth’s mantle in high temperature and under extreme pressure – this process can result in a variety of internal characteristics called ‘inclusions’ and external characteristics called ‘blemishes.’
The GIA Diamond Clarity Scale has 6 categories, some of which are divided, for a total of 11 specific grades.
- Flawless (FL) No inclusions and no blemishes visible under 10x magnification
- Internally Flawless (IF) No inclusions visible under 10x magnification
- Very, Very Slightly Included (VVS1 and VVS2) Inclusions so slight they are difficult for a skilled grader to see under 10x magnification
- Very Slightly Included (VS1 and VS2) Inclusions are observed with effort under 10x magnification, but can be characterised as minor
- Slightly Included (SI1 and SI2) Inclusions are noticeable under 10x magnification
- Included (I1, I2, and I3) Inclusions are obvious under 10x magnification which may affect transparency and brilliance
Carat. The diamond Carat is last but not least, it refers to the weight of the diamond, not how large the diamond is. The weight of a 1 carat diamond is 200 milligrams and each carat is subdivided into 100 points. Jewellers often describe the weight of a diamond below one carat by its points.