Diamond Clarity: The Guide to Inclusions, Blemishes & Grading
When shopping for a diamond, one of the most overlooked but impactful qualities is clarity. Clarity directly affects how a diamond sparkles, how durable it is, and how much it costs. Whether you're looking for a flawless stone or a great-value eye-clean diamond, understanding diamond clarity is essential to making a confident and informed purchase.
What Is Diamond Clarity?
Diamond clarity is a crucial factor that influences a diamond's beauty, durability, and overall value. It refers to the presence and visibility of internal characteristics (inclusions) and external imperfections (blemishes) within a diamond. These imperfections can form naturally during the diamond's creation or result from cutting, polishing, or everyday wear. The clarity grade is determined by examining these features under 10x magnification and ranges from Flawless (FL) to Included (I).
Why Diamond Clarity Matters
Diamond clarity plays a key role in how a diamond looks, performs, and lasts over time. Highly included diamonds may appear dull, less brilliant, and more prone to cracking or chipping. Flawless and Internally Flawless diamonds are rare and prized for their purity, but diamonds with slightly lower clarity grades—especially VS and SI—can still look stunning and offer excellent value. Ultimately, clarity should be evaluated alongside the other 4 C's (cut, color, and carat) for a complete assessment of quality.
What Is the Diamond Clarity Scale?
The International Gemological Institute (IGI) classifies clarity into six categories, comprising 11 specific grades. Each grade reflects the number, size, location, and visibility of inclusions and blemishes when viewed under 10x magnification:
| Clarity Grade | Visibility (10x) | Eye-Clean | Notes |
|---|---|---|---|
| FL | No inclusions or blemishes | Yes | Extremely rare and valuable |
| IF | No internal inclusions | Yes | Only surface blemishes are visible |
| VVS1/VVS2 | Extremely difficult | Yes | Nearly flawless to professionals |
| VS1/VS2 | Minor inclusions | Often | Best value-to-clarity ratio |
| SI1/SI2 | Noticeable | Sometimes | Depends on the inclusion location |
| I1–I3 | Obvious to the unaided eye | Rarely | May affect brilliance/durability |
Below is a breakdown of each clarity grade to help you better understand what to expect:
Flawless (FL)
These diamonds have no inclusions or blemishes visible under 10x magnification. They are extremely rare and represent the highest clarity grade available.
Internally Flawless (IF)
Internally Flawless diamonds contain no internal inclusions, though they may have minor surface blemishes. To the naked eye, they appear perfect.
Very Very Slightly Included (VVS1, VVS2)
These diamonds feature extremely minute inclusions that are very difficult to detect, even for trained gemologists. VVS diamonds are always eye-clean and offer exceptional clarity.
Very Slightly Included (VS1, VS2)
VS diamonds have minor inclusions that are somewhat easy to detect under 10x magnification but not visible to the naked eye. They provide an ideal balance of quality and value.
Slightly Included (SI1, SI2)
These diamonds contain inclusions that are noticeable under magnification and may be visible without it. However, many SI diamonds—especially SI1—can still be eye-clean, depending on inclusion size and placement.
Included (I1, I2, I3)
Diamonds in this category have inclusions that are obvious under 10x magnification and often visible to the unaided eye. They may impact the diamond’s brilliance and durability.
Eye-clean refers to a diamond that appears free of visible inclusions to the naked eye when viewed from the top.
How Is Diamond Clarity Graded?
Certified gemologists evaluate clarity based on a range of standardized criteria:
- Size: Larger inclusions have more impact on clarity.
- Number: Multiple inclusions generally lower the grade.
- Position: Inclusions in the center or table area are more visible and impactful.
- Nature: The type of inclusion (e.g., cloud, feather, crystal) affects severity.
- Relief: The contrast between the inclusion and the diamond’s body.
These characteristics are carefully documented and mapped in a clarity plot as part of the diamond’s IGI certificate.
Types of Diamond Inclusions and Blemishes
Diamonds, whether natural or lab-grown, commonly feature internal and external imperfections. Understanding them can help you choose a better stone.
Internal inclusions:
- Feathers: Small internal fractures that may affect durability.
- Pinpoints: Tiny dot-like crystals.
- Clouds: Groups of pinpoints that cause a hazy appearance.
- Crystals: Mineral deposits inside the stone.
- Needles: Thin, elongated inclusions.
- Knots: Crystals that extend to the surface.
- Graining: Internal growth lines that may look like streaks or reflections.
External blemishes:
- Scratches: Fine surface lines caused during polishing or wear.
- Chips: Small, shallow breaks along edges or facets.
- Abrasions: Minor scuffing on facet junctions.
- Naturals: Portions of the rough diamond left unpolished.
- Pits: Tiny indentations on the surface.
Diamond Clarity Buying Tips
When selecting a diamond, clarity should be balanced with your overall preferences and budget. Consider the following tips:
- Prioritize Eye-Clean Diamonds: Diamonds graded VS1, VS2, and even some SI1s appear flawless to the naked eye, offering excellent value. ("Eye-clean" means no visible inclusions without magnification.)
- Match Clarity to Diamond Size: In larger diamonds, inclusions are easier to see, so higher clarity may be necessary.
- Consider the Cut Style: Step cuts like emerald or Asscher are more transparent, so they reveal inclusions more easily than brilliant cuts.
- Inspect Stones Personally or via HD Media: High-resolution images or videos help you judge clarity more accurately.
- Evaluate Inclusion Placement: Inclusions near the edges or under prongs may be concealed by settings.
- Shape Matters: Brilliant shapes (oval, cushion, radiant, pear, marquise) better disguise inclusions than step cuts.
Clarity vs. Other 4 C’s
While clarity is an important aspect of a diamond's quality, it's only one part of the 4 C's—cut, color, clarity, and carat. Understanding how clarity compares to the other Cs can help you make smarter trade-offs:
- Clarity vs Cut: Cut has the greatest impact on a diamond’s brilliance and sparkle. A diamond with a lower clarity grade but excellent cut can look more dazzling than a flawless diamond with a poor cut.
- Clarity vs Color: Color affects how white or tinted a diamond appears. In many cases, a slightly lower clarity grade can be offset by choosing a higher color grade for a brighter visual appeal.
- Clarity vs Carat: Larger diamonds reveal inclusions more easily. If size is a priority, you may need to balance it with a slightly lower clarity to stay within budget.
For most shoppers, it’s better to aim for a well-cut, eye-clean diamond with good color balance rather than prioritizing a flawless clarity grade that may not be noticeable to the naked eye.
Conclusion
Clarity is one of the most misunderstood yet impactful aspects of diamond quality. While flawless stones are highly prized, many lower-clarity diamonds offer near-identical beauty for a fraction of the cost—especially if they are eye-clean. Additionally, lab-grown diamonds often have fewer inclusions due to controlled growing environments, though they may contain growth remnants or metallic inclusions unique to the process.
As you assess diamond options, remember that clarity should not be viewed in isolation. Evaluate it alongside cut, color, and carat to find a diamond that best fits your needs. Whether you’re shopping for a breathtaking centerpiece or a smart investment, understanding clarity empowers you to choose with confidence.