The idea that all lab-grown diamonds are flawless is a common misconception that stems from their controlled creation environment. Lab-grown diamonds are chemically, physically, and optically identical to natural diamonds, meaning they are subject to the same formation of imperfections. These diamonds are grown in a laboratory under conditions that mimic the earth’s natural processes. Just like their mined counterparts, they are rarely produced without any internal or external characteristics. The presence of these characteristics, known as inclusions and blemishes, is proof that the diamond is a real crystalline structure.
The Reality of Lab-Grown Diamond Clarity
The term “flawless” (FL) is a specific, top-tier clarity grade that is rare for any diamond, whether grown in a lab or mined from the earth. Most lab-grown diamonds (LGDs) fall into the Very Slightly Included (VS) or Slightly Included (SI) categories, which are still considered high-quality. Inclusions are internal features that form during the diamond’s growth, such as trapped crystals or structural irregularities. Blemishes are external surface marks that occur during the cutting and polishing process.
The existence of these imperfections is a natural byproduct of the diamond’s rapid crystallization process in the lab. While the environment is controlled, it is not perfect, and trace elements or foreign particles can be introduced. The clarity grade is determined by the size, number, location, and nature of these characteristics when viewed under 10x magnification.
How Imperfections Form During Growth
The specific types of imperfections found in a lab-grown diamond are often determined by the growth method used. The High-Pressure/High-Temperature (HPHT) method mimics the earth’s conditions, using metal solvents and catalysts to dissolve the carbon source. This process frequently results in the trapping of metallic flux, such as iron, nickel, or cobalt, which appear as small, dark, opaque inclusions within the diamond.
The Chemical Vapor Deposition (CVD) method involves depositing carbon atoms onto a seed crystal in a vacuum chamber. CVD diamonds can exhibit dark non-diamond carbon spots or internal strain lines, which appear as faint striations or graining patterns. These features are caused by uneven growth or the presence of uncrystallized carbon during the deposition process. Both methods produce diamonds with unique, identifiable imperfections.
Understanding the Clarity Grading Scale
Clarity is assessed using a standardized scale developed by gemological institutions, which ranges from Flawless (FL) to Included (I3). The grade is assigned based on the visibility of inclusions and blemishes under 10x magnification.
For the average buyer, the most practical consideration is whether a diamond is “eye-clean,” meaning the inclusions are not visible without magnification. Diamonds graded as Slightly Included (SI1 and SI2) often represent the best value, as their inclusions are typically not visible to the unaided eye, even though they are noticeable under 10x magnification.
Clarity Grades
- Flawless (FL) diamonds have no visible characteristics.
- Internally Flawless (IF) stones may have minor surface blemishes but no internal inclusions.
- Very, Very Slightly Included (VVS1 and VVS2) contain inclusions that are extremely difficult for a trained grader to see.
- Very Slightly Included (VS1 and VS2) diamonds have minor inclusions that are difficult to somewhat difficult to see under magnification.
Clarity Comparison to Natural Diamonds
Lab-grown diamonds and natural diamonds are graded using the same clarity scale, but the types of inclusions they contain often differ. Natural diamonds typically contain mineral crystals or geological remnants trapped during their formation deep within the earth. In contrast, LGDs are characterized by process-specific inclusions, such as metallic flux in HPHT diamonds or distinct growth patterns in CVD diamonds.
Lab-grown diamonds tend to have a higher average clarity grade than natural diamonds because their growth environment is more controlled. This higher average does not mean every LGD is flawless; it means a greater percentage achieve grades in the VVS or VS range. The presence of inclusions in both types of diamonds confirms their status as real crystalline carbon structures.