What is a diamond report?


The NGL Diamond Grading Report is a document detailing the examination of your diamond. It includes all important characteristics of your diamond, such as cut, color, clarity, carat weight, fluorescence, dimensions, etc. Every diamond is unique and requires its own report, since every diamond was exposed to different ground conditions. Despite their underground formation, they are susceptible to above- surface conditions such as scratches, inclusions, blemishes, etc., all of which are detailed in your NGL report.

When making a report, we inspect your diamond under a microscope to determine the “4C’s” - Carat weight, Color, Clarity, and Cut, plus some additional information detailed below. 


What does the NGL report show?


The NGL report includes the following factors that characterize your diamond:


Report Number


Each report receives an identification number issued by us. This number is used as reference when the diamond is sold.




The diamond’s length, width, and depth are measured in millimeters and presented in the report.


Color Grade:


Most diamonds are graded on a colorless scale, meaning, based on the absence of color. Many have yellow, brown, or grey hues formed by natural elements. Much fewer diamonds are white. It is this rarity that makes the white diamonds higher in value. Therefore, they are graded higher on the colorless scale. Fancy color diamonds, on the other hand, are graded on a color scale – the more saturated the color, the higher the value.

The colorless grade is classified by letters – from D to Z. D colors are colorless and highest in value. E and F are colorless with a minute hue.  G – J have a subtle yellow hue. K to X have a very strong yellow hue, and X,Y, and Z diamonds exhibit a lot of color.


Shape and cut


Diamonds can be cut in various shapes, mainly the following:

  • Pear Shape
  • Emerald Cut
  • Oval
  • Round Brilliant Cut
  • Cushion Cut
  • Old European Cut
  • Marquise
  • Rose Cut


The cut is the relation between the angles and proportions of the different facets. The proportions of the angles of each facet impact light reflection, brightness, fire, and scintillation – in other words, brilliance. The better the cut, the more brilliant the diamond and the higher its value.

The cut scale:

  • Excellent
  • Very Good
  • Good
  • Fair
  • Poor

Carat Weight:


The diamond’s weight is defined in carats and indicated in the report. A metric carat equals 200 milligrams. Each carat is divided into 100 ‘points’, allowing a more precise measurement. Often, the weight of a diamond below one carat is described by its points alone. Meaning, a diamond that weighs 0.25 carats is described as a ‘twenty-five pointer.’ 


Clarity Grade:


Clarity is defined by the absence of inclusions or blemishes.

Inclusions are formed inside the diamond as a result of overwhelming heat and pressure during the diamond’s formation, or foreign materials caught in the diamond during its growth. These inclusions can be black carbon spots, crystals, feathers, and graining. Blemishes are formed on the outer surface due to human wear and tear, and they include chips, abrasions, and scratches. 

Grading in this scale is also by letters, as follows:

  • Flawless (F) 
  • Internally Flawless (IF)
  • Very Very Slightly Included (VVS1, VVS2)
  • Very Slightly Included (VS1, VS2)
  • Slightly Included (SI1, SI2)
  • Included (I1, I2, I3)



After a diamond is cut, it is polished to achieve a smooth finish. Sometimes this process can damage the diamond, but the damage is normally invisible to the human eye. The gemologist will normally look for these damages through the microscope. The less damaged the diamond, the better the polish and the higher the value.

The polish scale is as follows:

  • Excellent
  • Very Good
  • Good
  • Fair
  • Poor



Symmetry is the proportional alignment of the diamond’s crown angles, height variation, girdle thickness, lower half percentage variation, misshapen facets, pavilion depth variation, table alignment, and more. Symmetry also affects the light reflection in the diamond.


The symmetry scale is as follows:

  • Excellent
  • Very Good
  • Good
  • Fair
  • Poor


Fluorescence is the UV impact on the diamond. Diamonds with faint or medium fluorescence are slightly hazy. Diamonds with strong fluorescence have a milky appearance, with a prominent and saturated glow in UV light. The lesser the fluorescence, the higher the value.

Grading scale for fluorescence: 

  • None
  • Faint
  • Medium
  • Strong
  • Very Strong

Laser Inscriptions:

The report indicates whether its number is laser- inscribed on a diamond’s girdle.


The report will present an image of the diamond’s measurements.

Clarity Characteristics:

The report will show a map or a diagram of all inclusions in the diamond.

Diamond report NFT:

We provide an NFT for the report, a tokenized digital certificate recorded in the blockchain ledger. This NFT is provided free of charge, as part of our laboratory services. The NFT provides several advantages – a. It is a digital proof that the diamond is not counterfeit, lost or stolen, thereby protecting the market from counterfeiting and money-laundering. b. As NFT trade is growing worldwide, it may have a value of its own in the future, independent of the diamond’s value.

All of the aforementioned characteristics affect the diamond’s value and will be presented accurately in our reports, so that you can make the best choice when buying or selling a diamond.

For more information about our testing and reporting services,

Contact NGL Labs in this link.