Explaining Diamonds - The 4 C’s


A carat is a unit of measurement for the weight of a diamond with one carat equalling to 200 milligrams, or 0.2 grams, also known as 100 points. Since larger diamonds are harder to find than smaller ones, the price of diamonds with respect to their carat weight goes up exponentially.
The image below shows an example of the change in carat weight with change in the diameter of a round diamond. But keep in mind that two diamonds of the same weight could have different sizes. Why? If a diamond is cut too shallow (or flat) it will have a larger diameter, but shallow depth and appear larger. Likewise, if a diamond is cut too deep (or pointed) it will have a smaller diameter and deep depth and appear smaller. This is why cut is so important.



A diamond's clarity is a measurement of the amount of blemishes (external flaws) or inclusions (internal flaws) a diamond contains. An inclusion can be seen as air bubbles, cracks, and non-diamond minerals found in the diamond.
The grading starts at F (FLAWLESS) which is a completely flawless (internally & externally) and extremely rare diamond. The chart below is a GIA clarity scale showing the different grades of diamond clarity.



The colour grading for white diamonds starts from completely colourless (most expensive) to a faint yellow. The colour in a diamond is produced from chemical impurities contained in it's composition. The whiter or colourless the diamond, the more brilliant it will be because it will allow more light to pass and be reflected back. Also the whiter the diamond, the more colours it will reflect back to achieve that desirable rainbow brilliance only a well-cut, colourless diamond can create.
The chart below shows the colour grading created by the Gemmological Institute of America (GIA) which is the professional colour scale for white diamonds.
Diamonds graded D - F are the rarest and most expensive, whereas the ones graded G - J are seemingly colourless to the untrained eye. The diamonds with grades K - Z are more noticeably yellower; however the choice always depends on the buyer's preference.


The colour grading for fancy coloured diamonds such as your Pink, Champagne and Yellow’s is very different from white diamonds, see Other types of Diamonds to learn more about these diamonds. Estrela recommend and supply colour G and above, others can be supplied at your request.




The cut of a diamond determines how a diamond shines; the cut does not refer to the shape of the diamond. The cuts on the diamond are referred to as Facets with an “Ideal” cut diamond, it will allow light through the top of the stone ( referred to as table) and travels to the pavilion where it reflects from one side to the other and back through the table to the observers eye.
If a diamond is cut poorly as per the diagrams, the light escapes and you are left with a rather dull looking diamond. The more symmetrical the cut is the more you will notice a brilliance about your stone, giving you this flashing, fiery effect that makes your diamond mesmerizing.