Clarity measures the presence and nature of inclusions (internal characteristics) and blemishes (surface characteristics) in a diamond. Both lab-grown and mined diamonds can have inclusions — they form during the crystallization process in either case. They're not defects in the traditional sense; they're the natural result of carbon atoms organizing under intense conditions.

The clarity scale was developed to assess how these characteristics affect the appearance and structural integrity of the diamond. Here's how to read it.

The Full Clarity Scale

FL — Flawless

No inclusions or blemishes visible under 10x magnification by a trained grader. Extremely rare. In lab diamonds, FL is somewhat more attainable than in mined diamonds, but it still carries a substantial premium. Unless you specifically want the best grade possible on paper, FL offers no practical advantage over VS2 in how the diamond looks in a setting.

IF — Internally Flawless

No internal inclusions under 10x magnification, though minor surface blemishes may be present. Also rare. The same practical consideration applies: IF and FL look identical to VS2 in real-world wear.

VVS1 and VVS2 — Very Very Slightly Included

Inclusions so small they're extremely difficult for even a trained grader to find under 10x magnification. VVS1 has inclusions more toward the edge of the stone; VVS2 inclusions may be slightly closer to center. Both grades are eye-clean by any definition — you will not see these inclusions without a loupe.

VVS grades carry a premium over VS grades that isn't justified by any visual difference in everyday wear. Recommended only if you specifically value the high clarity grade on the certificate.

VS1 and VS2 — Very Slightly Included

Minor inclusions that are difficult to see under 10x magnification but can be found upon close inspection. VS1 inclusions are harder to locate than VS2. Both grades are completely eye-clean.

VS2 is the most popular clarity grade purchased by knowledgeable buyers — it's the sweet spot. You get a demonstrably clean diamond with solid documentation, at a price meaningfully below VVS grades. This is Lihara's most recommended clarity range.

SI1 — Slightly Included 1

Inclusions noticeable under 10x magnification. Here's where it gets interesting for lab diamonds: SI1 stones are frequently eye-clean — meaning the inclusions are not visible to the naked eye at normal viewing distance. This is more consistently true in lab diamonds than in mined diamonds, because the types of inclusions that form in lab growth processes (typically metallic flux inclusions in HPHT, or pin-point clouds in CVD) tend to be transparent or very small.

An SI1 lab diamond that is eye-clean can be an excellent value buy. You're paying significantly less than VS2 for a stone that looks identical to VS2 in a ring. The key word is "eye-clean" — always confirm this for specific SI1 stones before buying.

SI2 — Slightly Included 2

Inclusions that may be visible to the naked eye. SI2 is much more variable — some are eye-clean, many are not. Requires careful evaluation before purchase. If buying SI2, you need to either view the stone or have a high-quality image/video of the actual stone (not a stock photo) to evaluate whether the inclusions are visible. Lihara doesn't recommend SI2 as a default choice without this evaluation step.

I1, I2, I3 — Included

Inclusions visible to the naked eye that affect appearance and potentially structural integrity. Avoid for fine jewelry worn regularly. These grades compromise the diamond's appearance and durability.

Types of Inclusions in Lab Diamonds

The type of inclusion matters almost as much as its size and location. Common inclusions in lab diamonds:

  • Metallic inclusions (HPHT diamonds): Tiny metallic flux remnants from the growth process. Usually dark and small. In small quantities, they're invisible to the naked eye and don't affect light performance.
  • Pin points (CVD diamonds): Extremely small crystal or void inclusions. Often transparent. At VS2 and above, completely invisible in wear.
  • Clouds: Groups of pin points that can appear as a haziness under magnification. If large, a cloud can affect transparency — this is why a single clarity grade isn't sufficient; the clarity plot on the IGI report matters too.
  • Feathers: Small fractures. In VVS–VS grades, feathers are very small and pose no structural risk. In SI2–I grades, larger feathers can theoretically affect durability.

Location of Inclusions Matters

An inclusion in the center of the table (the flat top facet of a round brilliant) is more visible than the same inclusion near the girdle (edge) of the stone. The IGI clarity plot on your certificate shows exactly where each inclusion is located.

A VS2 diamond with an inclusion hidden under a prong in a prong setting is effectively invisible. An SI1 diamond with a small, off-center inclusion near the girdle may look cleaner than a VS1 diamond with a center-table inclusion — even though the grade suggests otherwise. Use the clarity plot.

Clarity and Different Diamond Shapes

Some shapes show inclusions more easily than others:

  • Round brilliant: The facet pattern creates maximum light scattering, which hides inclusions well. VS2–SI1 works beautifully.
  • Oval, cushion, pear: Similar to round in terms of inclusion masking. VS2–SI1 generally fine.
  • Emerald, asscher (step cuts): The long, open facets act like windows — inclusions are much more visible in these cuts. For step cuts, target VS1 or better.
  • Princess: Intermediate — more inclusion-masking than step cuts but less than rounds. VS2 is the minimum recommended.

The Practical Recommendation

  • Brilliant cuts (round, oval, cushion): Buy VS2 without reservation. Evaluate SI1 stones individually if budget is a constraint.
  • Step cuts (emerald, asscher): Buy VS1. Don't go below VS2.
  • All shapes: Don't pay FL or VVS premiums unless the certificate grade matters specifically to you.

Frequently Asked Questions

What does "eye-clean" mean?
A diamond where no inclusions are visible to the naked eye at normal viewing distance (12 inches). VS2 is always eye-clean. VS1, VVS1, VVS2 are eye-clean. Many SI1 lab diamonds are eye-clean. SI2 may or may not be — evaluate case by case.

Are inclusions in lab diamonds different from mined diamonds?
Yes, slightly. The types of inclusions vary by growth method. But the grading scale and visual impact are the same. A VS2 lab diamond looks as clean as a VS2 mined diamond.

Does clarity affect sparkle?
Very minimally at VS2 and above. Large inclusions in I1–I3 grades can interfere with light performance. Within the VS–SI1 range, cut has far more impact on sparkle than clarity.

Shop Certified Lab Diamonds at Lihara

Every Lihara diamond comes with an IGI grading report specifying clarity grade, inclusion type, and a clarity plot. You know exactly what you're buying.

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