The 4Cs | Eliyahu Yona Diamonds

The 4Cs

The first evidence of diamonds were found in India in 4th century BC, but it wasn’t until 1870 that the first full scale diamond operation was launched. Since then diamonds have been highly valued and sought after. However, with a variation on quality and color, it wasn’t until the 20th century that the diamond community devised an agreed upon method of assessing the quality of a diamond. The Gemological Institute of America (GIA) founded a grading system for diamonds known as the the 4C’s and is the global authority for the quality of diamonds. The 4C’s stand for Color, Cut, Clarity and Carat.


The cut of a diamond refers to how well a diamond’s facets can reflect light. From all four C’s, the cut is the feature that most determines its final beauty. The cut can only be determined by the most experienced diamond specialist, and will be decided upon by three factors; the fire, brilliance and scillinatation. When cut is referred to, it’s only relevant to round shaped diamonds.

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All diamonds have some small imperfections, also known as inclusions, and these are measured on a scale (IF, VVS1, VVS2, VS1, VS2, SI1, SI2, I1, I2, I3). These inclusions are hardly ever seen by the naked eye and would need magnification, however they can still affect the value of a stone dramatically.

IF – Internally Flawless and means there are no internal flaws, but some surface flaws. Understandably, these are very rare.

VVS1-VVS2 – Very Very Slightly Included (two grades). The stone has tiny inclusions which are very difficult to detect without a 10x magnification by a trained gemologist.

VS1-VS2 – Very Slightly Included (two grades). Minuscule inclusions seen only with difficulty under 10x magnification.

SI1-SI3 – Slightly Included (two grades). Very small inclusions more easily detected using 10x magnification.

I1-3 – Inclusions which are large enough to be visible both using 10x magnification and to the human eye.

clarity 1clarity 1


When diamond ‘color’ is referred to, we are actually referring to the lack of color in a diamond. The less of a color in a diamond, the more pure and higher the value. The GIA has a D-Z scale of color from the completely colorless (D) to light (Z). Naturally colored diamonds, are not considered in this scale. They are known as ‘fancy colored’ diamonds and are graded on a different scale.


A Carat is the unit of weight used for weighing diamonds. Naturally, as the carat weight increases, so does the price. A carat unit is equal to 0.2 grams, and although the carat unit is important, the stone must still meet the criteria of the other three C’s to be highly valued.

The Fifth C - Certification

To ensure that a diamond is properly evaluated, it must go through a certification procedure. The certification is issued through a reputable gemology lab and an experienced diamond grading expert.