Carat is the metric to measure the weight of the diamonds, each carat is divided into 100 points, for example a diamond of 100 points weighs 1.00. The weight of the diamond is the main factor in determining the value of a diamond, for determine the price also the quality plays a mainly role.
At the begging diamonds used to be measured by its size and not by its carat weight, now two diamonds with the same weight could have different sizes, it depends on the cut.
Cut is very important. A properly cut diamond will both yield a good face up size and sparkle well. This is why it’s important not just to get the biggest diamond you can afford, but the best cut diamond as well.
this measures the diamond’s flaws (internal or external inclusions) and impurities. The best diamonds are those free of flaws and inclusions, where the light doesn’t find any interferes in passing through the diamond. The analysis of clarity can be only done by experts and gemologists by a 10x magnification view. The lack of clarity affects the beauty of the diamond but not its durability.
GIA DIAMOND CLARITY SCALE
|FL||Flawless:No inclusions or blemishes are visible to a skilled grader using 10x magnification.||Extremely rare, less than 1 in 5000 jewelry quality diamonds are rated FL.|
|IF||Internally Flawless:No inclusions, only blemishes are visible to a skilled grader using 10x magnification.||FL and IF diamonds appear identical unless viewed under 10x magnification by a skilled grader. Less than 3% of jewelry quality diamonds are rated IF.|
|Very, Very Slightly Included:Inclusions are difficult for a skilled grader to see under 10x magnification.||VVS1 inclusions are typically only visible from the pavilion, while VVS2 inclusions are visible from the crown. In each, the inclusions are invisible to the eye, appearing identical to the higher grades unless viewed under 10x magnification by a skilled grader.|
|Very Slightly Included:Inclusions are clearly visible under 10x magnification but can be characterized as minor.||Inclusions are not visible to the naked eye. Perhaps 1 in 100 untrained observers can detect VS2 inclusions with the naked eye, on close inspection under ideal conditions.|
|Slightly Included:Inclusions are noticeable to a skilled grader using 10x magnification.||SI1 is the lowest grade with flaws often invisible to the naked eye. SI2 inclusions are usually visible to the naked eye, although they will require close inspection.|
|Included:Inclusions are obvious under 10x magnification and may affect transparency and brilliance.||I1 diamonds have inclusions that are almost always visible to the naked eye.
Because I2-I3 diamonds have prounounced inclusions, and in the case of I3 may even affect the diamond’s durability, they are not offered by Lumera.
The color of a diamond varies from totally colorless to light yellow. The differences aren’t obvious so is quite difficult to distinguish it and determine it.
It’s wrong to confuse the cut of a diamond with its shape. The cut is about the general precision and quality of the overall cutting. This is the C more difficult to evaluate, even the different labs haven’t reach an agreement. The diamond’s cut usually considers three criteria: proportions, symmetry and polish. Symmetry measures how well the facets match the other facets while polish is a measure of the surface finish.