The 4Cs of Lab Grown Diamonds: Everything You Need to Know
When shopping for a diamond—whether it's for an engagement ring, a timeless piece of jewelry, or a special gift—understanding the 4Cs is essential. The 4Cs are the global standard originally created by the Gemological Institute of America (GIA) for evaluating diamond quality and include Cut, Color, Clarity, and Carat Weight. These characteristics directly impact a diamond’s beauty, brilliance, and price.
Since lab grown diamonds are physically, chemically, and optically identical to mined diamonds, the same 4Cs grading system applies. Knowing how to evaluate these factors will help you choose the perfect diamond for your needs without overpaying for qualities that may not be as important to you. Luckily, with lab grown diamonds, you often won't need to compromise on the quality of the diamond and can still find exactly what you want within your budget.
Cut
Cut is the most important of the 4Cs because it determines how well a diamond interacts with light, creating brilliance and fire. A well-cut diamond maximizes sparkle, while a poorly cut diamond can look dull—even if it has perfect clarity and color.
How is Cut Graded?
Only round brilliant diamonds receive standardized cut grades because their proportions and light performance can be consistently measured. The Gemological Institute of America (GIA) and International Gemological Institute (IGI) grade round diamonds from Excellent to Poor based seven components – brightness, fire, scintillation, weight ratio, durability, polish and symmetry.
Fancy shapes (like ovals, cushions, emeralds, etc.) have more variation in their proportions and style preferences, making a universal cut grading system more difficult. They do not receive an official cut grade, but factors like depth, table size, and facet alignment still affect their brilliance.
Both round and fancy shape diamonds are graded for polish and symmetry, which play a major role in light performance and overall beauty. With lab grown diamonds, aim for Excellent in both, especially if investing in a larger stone.
Cut Grades:
- Ideal - Outstanding sparkle and symmetry. Cut to perfect proportions for refracting light.
- Excellent - Exceptional sparkle and even patterns; reflects nearly all light that enters.
- Very Good – Excellent brilliance with slight differences in proportion.
- Good – Still reflects light well, but may appear slightly less lively.
- Fair – Noticeable reduction in sparkle, not always symmetrical.
- Poor - Appear dull and asymmetrical; much of the light escapes from the sides and bottom.
What to Look For:
- For round diamonds, prioritize Excellent or Ideal cut grades for maximum sparkle.
- For fancy shapes, look at length-to-width ratios based on your personal preference and aim for Excellent symmetry and polish.
- Depth and Table % influence how light enters and reflects through the diamond. Avoid diamonds that are too shallow or too deep, as they lose light and appear lifeless.
- For elongated fancy shapes like ovals pears, and marquise, avoid strong bow-ties—a dark shadow in the center.
Color
Diamond color refers to the absence of color in a diamond, graded on a scale from D (colorless) to Z (light yellow or brown). Diamonds can contain trace elements like nitrogen or boron that affect color, although it is usually minimized in lab grown diamonds.
With mined diamonds, the difference between colorless (D-F) and near-colorless (G-J) can mean thousands of dollars, making G-H a popular choice for balancing beauty and value.
However, with lab grown diamonds, the price difference between D-F and G-J is much smaller, making it more accessible to choose a colorless diamond without breaking your budget.
Diamond color refers to the absence of color in a diamond, graded on a scale from D (colorless) to Z (light yellow or brown). Diamonds can contain trace elements like nitrogen or boron that affect color, although it is usually minimized in lab grown diamonds.
With mined diamonds, the difference between colorless (D-F) and near-colorless (G-J) can mean thousands or even tens of thousands of dollars, making G-H a popular choice for balancing quality and value.
However, with lab grown diamonds, the price difference between colorless and near colorless is much smaller, making it more accessible to choose a colorless diamond without breaking your budget.
Lab diamonds can sometimes display subtle blue, gray, or brown undertones—even if they receive a high color grade like D, E, or F—although they are more likely found in lower color grades. This is often due to trace elements introduced during the growth process, like boron or nickel. These tints may not always be noted on the grading report, so it's important for you or a trusted jeweler to view the diamond in person or request photos and videos before purchasing.
What to Look For:
- D-F (Colorless): Most lab grown diamonds fall in this range due to precise production methods. Ideal for those who want a pure, icy-white look.
- G-H (Near-Colorless): Still appears white with a slightly warmer tone, with minimal visible difference but a slightly lower price. You likely won’t find many lab diamonds below a G color as most are grown with a focus on achieving higher color grades.
Clarity
Clarity measures the presence of natural inclusions (internal marks) and blemishes (surface marks).
With mined diamonds, VS2-SI1 is often recommended as the sweet spot, offering an eye-clean look without the exponential price increase for higher clarity grades. Many jewelers will look for eye-clean SI diamonds to help their customers save, with small inclusions positioned in a way that are unable to be seen with the naked eye.
Lab grown diamonds tend to have fewer inclusions than mined diamonds because they form in a controlled environment over a relatively short period of time, rather than deep within the earth under unpredictable conditions over billions of years. Many lab diamonds fall in the VVS1-VS2 range as standard, meaning buyers can afford a cleaner, more flawless diamond without a huge price difference.
Clarity Grades:
-
Flawless (FL) & Internally Flawless (IF): No visible imperfections under 10x magnification.
*It's not necessary, but if you want a truly flawless diamond you will find more options with lab grown at a fraction of the mined diamond price. -
VVS1-VVS2 (Very, Very Slightly Included): Nearly perfect with tiny inclusions invisible to the naked eye.
-
VS1-VS2 (Very Slightly Included): Best balance of quality and value—flaws are microscopic.
-
SI1-SI2 (Slightly Included): Some inclusions may be visible to the naked eye, but many SI1 diamonds appear eye-clean.
-
I1-I3 (Included): Noticeable inclusions that can affect durability and appearance.
What to Look For:
-
VVS1-VVS2: Nearly flawless and without an untrained eye, inclusions may not even be detectable under magnification.
- VS1-VS2: A great balance of clarity and price—most lab diamonds in this range are completely eye-clean. Opt for VS1 for fewer inclusions.
Carat Weight
Carats are one of the most objective measurements of the 4Cs for determining the value of a diamond. It directly corresponds to the physical weight of a diamond, while other Cs are more subjective. One carat is equal to 200 milligrams or 1/5 of a gram.
While carat weight refers to a diamond’s size, it’s important to note that carat doesn’t necessarily equal visual size. A well-cut diamond with a lower carat weight can appear larger than a heavier diamond with poor cut and proportions.
Also, different shape diamonds will look visually different in size. Elongated shapes like Ovals, Pears, and Marquise can look larger than the same carat weight of a Round diamond. Asschers and Cushions have more depth to their cut, carrying more weight in the bottom of the diamond—meaning they will face up smaller than other shapes.
Lab grown diamonds cost significantly less per carat than mined diamonds, making it easier to afford larger stones without compromising on quality.
What to Look For:
- Whatever you like! Your budget
goes a lot further with lab grown diamonds, so the diamond carat weight of your dreams might be closer to your budget than you think.
Ratio
While not one of the 4 Cs, a diamond's length to width ratio is a crucial factor in a diamond's overall shape and look.
For elongated diamond shapes like ovals, pears, emerald, radiants, and marquise, the ratio affects how elongated or chunky the diamond will look. The "ideal" ratio is mostly based on personal preference and varies for different diamond shapes, but there is a range you want to stay within to prevent affecting the brilliance and cut.
Finding the Right Balance
With mined diamonds, shoppers often compromise between color, clarity, and size to stay within budget. But lab grown diamonds reduce the need for those tradeoffs. Because lab diamonds cost significantly less, you’ll often find higher color and clarity grades—like D-F and VS1+—and Excellent or Ideal cut diamonds at accessible prices.
That means you can choose a stunning, high-quality diamond without needing to “settle” for lower specs. You can get a bigger, more brilliant stone without compromising.
One last note: with engagement rings, bigger may not always be better! Consider what size looks flattering on your hand, as well as what suits your lifestyle. A 10 carat diamond would of course be stunning, but if you are someone who is very active and physical with your hands, it may not be the best option for every day.
Again, one of the key benefits to lab grown diamonds is that you are less constrained by any factors and can find the perfect diamond for you.