Diamond Education - The 4C's

Learning the main characteristics of diamond grading is the best way to start. These have been nicknamed The Four C's.

Cut (or Make)

The most important of the Four C's, Cut refers to the proportions of the way the stone has been physically cut making it the only grading factor that is not predetermined by nature.

The angles and size, shape and layout of the facets on a diamond are based on very specific optical calculations, which directly dictate how much the stone will sparkle.

Cut is graded as:

EXCELLENT         VERY GOOD         GOOD         MEDIUM         FAIR         POOR

Clarity

Due to the nature of the way a diamond crystal is formed, each stone will contain it's own unique internal characteristics. These are called inclusions or carbon flaws. Clarity is graded on how visible these characteristics are, and how they effect the overall look of the stone, both on inspection under magnification using a Loupe and with the naked eye.  

Clarity is graded:

LC       VVS1       VVS2       VS1       VS2       SI1      SI2       I1       I2       I3

(LC = Loupe clear - even study with a x10 loupe the stone appears clean of flaws. I3 = Included 3 - extensive covering of flaws or a major individual flaw).

Colour

Colour is graded by comparison. A Gemmologist will use a set of master stones to determine where a diamond will place in the colour spectrum.

While coloured diamonds such as yellow, pink and champagne, referred to as 'fancy', do exist and have encountered a renaissance of sorts in recent times, the most desired colour is still white.

Colour is graded on a spectrum from the letter D through to S-Z.

Carat (ct)

Carat is the terminology for the weight of a diamond. 1carat = 0.2grams.

A diamond that is cut in a round shape (or brilliant) and has a weight of 1 carat and has a good grade of CUT will measure 6.5mm in diameter.