The clarity grading of diamonds ranges from ‘IF’ (the perfect, internally flawless diamond) down to ‘I3’ (a stone with many inclusions that are visible even to the naked eye). Inclusions in diamonds can take the form of white ‘feathers’ that look like little cracks or can be black marks that look like grains of pepper encased in the diamond. The clarity scale is based on how noticeable the inclusions in the diamond are & not how many inclusions. ‘VVS1’ & ‘VVS2’ clarity diamonds have inclusions that are so small they can be easily missed even when looking through a jeweller’s loupe (a 10 times magnifier). ‘VS1’ & ‘VS2’ clarity are still very hard to spot through a loupe whilst ‘SI1’ & ‘SI2’ inclusions can be easily found when using a loupe.
Carat Weight
In round stones:
0.20ct = 3.8mm
0.25ct = 4.0mm
0.33ct = 4.4mm
0.50ct = 5.0mm
0.75ct = 6.0mm
1.00ct = 6.5mm
2.00ct = 8.0mm
In gold carat refers to the purity of the metal but in diamonds carat is simply a weight measurement. 1 carat = 0.2gms. The word ‘carat’ derives from ‘carob’ seeds. These seeds were used as a weight measurement at markets. Customers often took their own seeds to market to avoid dishonest traders who had 2 sets of carob seeds, one for buying & one set for selling! As the carat is such a tiny weight measurement most people have trouble imagining what a 1/4 ct or a 1/2 ct diamond would look like. It is for this reason that we have this chart which converts carat weights to millimeter sizes.