Diamond Education

A diamond by definition is made of crystalline carbon, known to be the hardest mineral. It has many uses as a gemstone in abrasives, cutting tools, and other applications. A natural diamond crystal is called a rough. The practice of changing a diamond rough into a faceted gem is called diamond cutting. After a diamond is cut, it is submitted to a gem lab for grading.

Like a human fingerprint, no two diamonds are the same. Each diamond contains its own unique traits and characteristics. Diamonds are characterized by four main features (The 4 C’s): Carat, Clarity, Color and Cut.

The 4 C’s

Carat Weight

The Carat weight measures the mass of a diamond (not to be confused with the measure of size). Diamonds are divided into 100 points. 100 points = 1 carat.

Source: http://www.gia.edu/gia-about/4Cs-Carat


Diamonds may naturally have inclusions and blemishes. Grading is based on how visible these characteristics are. A diamond with a Flawless grading (FL) has no inclusions or natural blemishes. A diamond with a Slight Inclusion (SI1-2) has slight characteristics that can be seen under 10X magnification.

Source: http://www.gia.edu/gia-about/4Cs-Clarity


A diamond’s color is graded on a scale from D to Z, which D being colorless and Z as yellow.

Source: http://www.gia.edu/gia-about-4Cs-Color


Cut is measured by a diamond’s proportions, symmetry and polish. Diamonds that have optimized proportions, symmetry and polish will have better interaction with light; this results in better brilliance, fire and scintillation of a diamond. The cut grading range is determined from Excellent to Poor.

Often, how a diamond is cut is the determining factor in the performance of a diamond. There are many methods to how a diamond can be cut. The most popular shape is the 58 facet round brilliant. Other brands have perfected their own cutting method (see Brands section).

Source: http://www.gia.edu/gia-about/4Cs-Cut

Please refer to GIA’s 4Cs guide: 

How to Pick Your Diamond


Diamonds come in a variety of shapes. Different shapes have different characteristics and quality. Some characteristics are valued more in some shapes than others.

Choose your diamond shape:

Carat, Cut, Clarity, Color

Determine what kind of characteristics you want your diamond to have. Pricing is determined by the combination of characteristics you choose.

Other Diamond Characteristics

Fluorescence – The fluorescence scale on a grading lab is determined from None to Very Strong. It is based upon a diamond’s effect to UV Lighting. In 95% percent of diamonds that exhibit fluorescence, the color is blue. According to studies, there has been no link between the appearance of a diamond and the strength of its fluorescence.

Source: http://4csblog.gia.edu/2012/understanding-diamond-fluorescence

Depth % The ratio of the total depth of the diamond (from table to culet) to the total diameter. For example, if the total depth of a round diamond is 4.00mm and the total diameter is 6.60mm, then the depth percentage is 60.6%. In most cases the depth % is rated:

  • Excellent = 60.1 - 62%
  • Good = 62 - 64%
  • Fair = 64 - 66%
  • Poor = over 66% / under 60%


Fancy Cuts (Princess, radiant, emerald) = 70 - 75% is acceptable

Table % The ratio of the table width to the total width of the diamond. In most cases the table % is rated:

  • Ideal = 53 – 58%
  • Excellent = 58.1 – 60%
  • Good = 60.1 – 64%
  • Fair = 64 – 70%
  • Poor = over 70%


Fancy Cuts (Princess, radiant, emerald) = 75 - 80% is acceptable


There are several diamond grading labs in the world. Every loose diamond sold at Carat & Co. will come with a GIA (Gemological Institute of America) or AGSL (American Gem Society Laboratories) certificate. These two laboratories are amongst the world’s most respected in their field, giving an unbiased, professional examination of your diamond. The diamond grading report will include your certificate number, diamond grading, and in some reports, a drawing of your diamond inclusions and blemishes. Before you buy your diamond, request for the diamond grading report and make sure your certificate number matches the laser inscription on your diamond.

Branded Diamonds

Hearts on Fire – The World’s Most Perfectly Cut Diamond®.

We proudly offer Hearts on Fire serialized diamonds. Less than a tenth of one percent of the world's diamonds can become Hearts On Fire. Combined with their proprietary diamond-cutting formula, they create a diamond that allows maximum shine and brilliance.

Cutting grade alone determines 50% of the diamond’s value. Hearts on Fire diamonds are cut at 100X power magnification (unlike the industry standard of 10X). This results in high brilliance and shine unlike any other. Hearts on Fire’s high-quality cut makes color and clarity less of a determining factor. They offer two groups of diamonds:

Sensational HOF Diamonds – G, H color. VS1 to SI1 clarity.
Signature HOF Diamonds – I, J color. VS1 to SI1 clarity.