About diamonds

The Gemological Institute of America (GIA) established in the 1940s the “4 Cs” and and The International Grading System™ which today is a de facto standard in the diamond industry.

The “4c’s” that evaluate the quality of a diamond are standards within how the diamond is cut, what the clarity of the diamond is, what color the diamond has and how many carats – the weight of the diamond is. Each of these 4 C’s is allocated a grade but many factors influence the grading within each “C”.

As the grading has a huge influence on the value of a diamond we’ve tried to summarize the characteristics for you in the following for you to understand how to value a diamond. 

We offer independently certified descriptions of our high jewellery collection that are issued by the recognized Institute de Gemmologie de Monaco (IGM) based on thorough laboratory research of each piece of jewelry.

The 4 C´s

Carat

“Diamonds and gemstones are weighed in metric carats: one carat is equal to 0.2 grams, about the weight of a paperclip.” 

Carat weight does matter. And as larger diamonds are much rarer than small diamonds price rise exponentially with weight. A 1 ct diamond will easily cost more than 4 times the price of a 0,5 ct diamonds with the same cut and quality.  

But the real question is at the same time what kind of cut your diamond has. The larger the surface on top of the diamond the more diamond there is to see. A well cut diamond will have more brilliance than a deep cut diamond or a shallow diamond. You will get the most brilliance in a well cut diamond.

In a diamond which is well cut (grades Very Good or higher), the light reflected out of the top making it appear larger. On the other side, a larger carat weight diamond could appear smaller with lower cut grades (Good, Fair and Poor).

Cut

“The sparkle and brilliance of a diamond depends more on its cut than anything else.”

A round brilliant cut diamond, which is the most common, has 57 or 58 facets. The GIA Diamond Cut Grading System for standard round brilliants in the D-to-Z color range is based on the assessment of seven components. 

The first three — brightness (the total light reflected from a diamond), fire (the dispersion of light into the colors of the spectrum), and scintillation (the pattern of light and dark areas and the flashes of light, or sparkle, when a diamond is moved) — are appearance-based aspects. The remaining four — weight ratio, durability, polish, and symmetry — are related to a diamond’s design and craftsmanship. 

All these components are summarized in one grade in a scale going from excellent to poor.

Clarity

“The absence of inclusions and blemishes makes a diamond rare and affects value.”

Because diamonds formed deep within the earth, under extreme heat and pressure, they often contain unique birthmarks, either internal (inclusions) or external (blemishes).

Diamond clarity refers to the absence of these inclusions and blemishes. Diamonds without these birthmarks are rare, and rarity affects a diamond’s value. Using the GIA International Diamond Grading System™, diamonds are assigned a clarity grade that ranges from flawless (FL) to diamonds with obvious inclusions (I3). The clarity is determined by looking at the diamonds with 10x magnification. Most diamonds fall into the VS (very slightly included) or SI (slightly included) categories.

Color

“Diamonds in the D-to-Z color range are valued by how closely they approach colorlessness – the less color, the higher their value.” 

Diamond color is all about what you can’t see. Diamonds are valued by how closely they approach colorlessness – the less color, the higher their value.

The scale begins with the letter D, representing colorless, and continues with increasing presence of color to the letter Z, or light yellow or brown.

A 1 ct. D diamonds could cost almost twice as much as a H color diamond with the same carat and cut.

Many of these color distinctions are so subtle as to be invisible to the untrained eye. But these slight differences make a very big difference in diamond quality and price.

The source for this article on the 4 C’s is GIA – Gemological Institute of America