A guide to the grading of lab grown diamonds

November 11, 2022

Who introduced The 4 C’s Of Lab Grown Diamonds?

The founder of the Gemological Institute of America (GIA), Robert M Shipley, introduced the 4 C's in 1953. This introduction brought uniformity and objective standards for jewelers and gemologists to grade and price diamonds. Although there are other grading systems, the GIA system is the most widespread in the world for lab grown diamonds.

For quite some time, the GIA has only been grading mined diamonds. It was only in 2007 that they started grading lab diamonds. It was in the year 2020 that the GIA started grading both mined and lab made diamonds in the exact same manner.

Grading Report Of Lab Grown Diamonds: 4 C’s

Let us understand the diamond grades of lab made diamonds through its 4 C’s.


Lab grown diamonds are available in both fancy-colored and transparent varieties.

Transparent Diamonds: As per the GIA diamond color grades, a diamond of any color is graded on a scale of D to Z. This scale gives a report of how transparent a diamond is. The higher the grade of the stone, the more transparent the diamond is.

  • The grades D, E, and F, come under the colorless category. Stones with a D grade are completely transparent, whereas E and F grade stones are less transparent than D.
  • Stones with G and J grades come under the near colorless category. They appear colorless except when they are put under observation.
  • Stones with K, L, and M grades come under the faint or “lightly tinted” category. When mounted in yellow or rose gold, these stones often appear colorless or "set white."
  • Stones have a stronger yellow or brown tint in the Very Light (N through R) and Light (S through Z) categories.

Fancy-colored diamonds: For colored stones, lab diamonds are graded based on tone, hue, and saturation.

  • Hue represents the color that is dominant in the stone.
  • Tone represents the relative lightness and darkness of the gemstone.
  • Saturation speaks about the intensity of the stone’s color.


As per the lab grown diamond guide, the cut of the stone is very important as it influences its overall beauty. An essential aspect of the diamond's cut is its proportions, angles, fire, brilliance, and finishing.

The grades on which the diamond cut is graded are – Ideal, Excellent, Very Good, Good, Fair, and Poor. Even if two lab grown diamonds belong to the exact grade, their cut may differ.

It is essential to understand the 4C's facts of lab grown diamonds so that you pay the right price for your investment. You should review the diamond's cut and seek advice from an expert, as its cut plays such an important role in its beauty.


A diamond clarity grades represent how transparent and clean a diamond is from inclusions and blemishes.

Let us understand the GIA clarity grading system –

Flawless - FL

  • Internally Flawless – IF is 100% eye clean.
  • Very, Very Slightly Included 1 – VVS1 is 99% eye clean.
  • Very, Very Slightly Included 2 – VVS2 is 99% eye clean.
  • Very Slightly Included 1 – VS1 is 95% eye clean.
  • Very Slightly Included 2 – VS2 is 85% eye clean.
  • Slightly Included 1 – SI1 is 50% eye clean.
  • Slightly Included 2 – SI2 is 15% eye clean.
  • Inclusions 1 – I1 is 1% eye clean.
  • Inclusions 2 – I2 is 0% eye clean.

Inclusions and blemishes in diamonds can interfere with the passage of light depending on their location, size, and darkness. The brilliant sparkle and beauty of the gemstone are dulled when there is an obstruction in the passage of light, thus taking away all the beauty of the brilliant cut.


Grading lab grown diamonds is incomplete without mention of the carat weight. ‘Carat’ represents the weight and not the size of the diamond.

Lab made diamonds between the carat weight of 1 and 3 are quite popular as they are affordable and within people's budget. HPHT diamonds can form as large as 10 carats with the highest being 15 carats. CVD diamonds form somewhere between 6 to 9 carats.

In addition to the carat, a diamond's overall shine and appearance should play an important role in determining its value.

The lab grown diamond buying guide of BLGD advises you to lessen your expenses on the clarity and color of the gemstone. Also, try to focus on something other than the stone's carat but on the cut, color, and clarity.

Make sure all four components are balanced when purchasing diamond jewelry for your loved ones or yourself.

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