In the process of evaluating and certifying diamonds, they are assessed based on four fundamental parameters which are called the 4Cs: cut, clarity, colour, and carat. These four properties then significantly influence the price of a diamond.
CUT: The right cut gives a diamond its radiant lustre. The most popular cut is a round one known as the brilliant cut. Diamonds can also be cut into a wide array of “fantasy” cuts which include the marquise, baguette, heart, teardrop, oval, and princess (a three-sided or four-sided cut with sharp corners which is especially popular for engagement rings).
CLARITY: Clarity is determined by the number, size, and distribution of any inclusions (internal impurities) in a diamond:
- IF (Internally Flawless) – clear diamonds without any inclusions,
- VVS 1, VVS 2 (Very Very Slightly Included) – diamonds with very small inclusions,
- VS 1, VS 2 (Very Slightly Included) – diamonds with small inclusions,
- SI 1, SI 2 (Slightly Included) – diamonds with inclusions which can be seen with a magnifying glass,
- I1, I2, I3 (Included), also labelled as “P” in the Czech Republic – diamonds with medium to larger inclusions visible to the naked eye.
COLOUR: The colour of colourless to yellow diamonds is evaluated based on an international scale:
- D to F – colourless diamonds;
- G to J – near colourless diamonds;
- K to M – diamonds with a touch of yellow;
- N to Z – diamonds with a brown-yellow colour.
Other colours of diamonds are simply called fancy. Some of our colour diamonds are treated to enhance their colour.
CARAT: The weight of diamonds is quoted in carats (ct), expressed to two decimal places, for example 0.25 ct. One (1) ct is equal to 0.2 grams. With earrings and jewellery which has multiple diamonds, we always state the total number of carats of all the diamonds.