Diamond Clarity Explained: Grade-by-Grade Visual Guide (2026)

Diamond clarity is the most misunderstood of the 4 Cs. Most buyers spend too much on it because they do not know where the visual threshold actually sits.

The 11 clarity grades

What matters: the naked-eye test

Clarity grading uses a 10x loupe. Normal viewing is no magnification. The question that matters: can I see any inclusions without a loupe at normal distance?

For most round brilliants and cushions, the answer is no for any grade FL through SI1. VS2 is the reliable eye-clean floor. SI1 usually passes eye-clean. SI2 sometimes does, sometimes not. I1 and below typically have visible inclusions.

Price impact (1ct lab-grown, G, EX cut, 14K solitaire)

SI1 to VS2: ~23% price increase. VS2 to VVS1: another ~35%. VVS1 to FL: another ~20%. Most of that money buys invisible differences.

Clarity by shape

Round brilliant: SI1 floor, VS2 target

57 facets break up light and hide inclusions well. SI1 typically eye-clean.

Cushion, oval, pear, marquise, radiant: SI1 floor, VS2 target

Modified brilliant cuts hide inclusions well. Same as round.

Princess: VS2 floor, VS1 target

Sharp corners can catch the eye. Verify inclusion placement away from corners.

Emerald, asscher: VS1 floor, VVS2 target

Step-cuts have large flat facets with no brilliant sparkle to break up light. Inclusions show clearly. Never go below VS1.

Inclusion placement matters as much as grade

What you cannot see without a loupe

Always invisible to naked eye:

• Pinpoints: Microscopic crystals.
• Small feathers: Thin internal fractures.
• Small clouds: Groups of pinpoints.
• Needles: Thin, straight white crystals.

Visible at lower grades:

• Large feathers: Visible at I1 and below.
• Dark crystals: Visible at SI2 and below.
• Chips/breaks: Visible at I1 and below.

Inclusion types and what they mean

Not all inclusions are equal. Grade alone does not tell you whether a specific stone will look clean or cloudy; the type and location of inclusions matter as much as the numerical grade. Common inclusion types:

• Pinpoints: Microscopic crystal specks, usually white. Invisible without magnification. Common at all clarity grades including VS.
• Feathers: Internal fractures that look like small feather shapes under magnification. Small feathers are invisible; large feathers become visible at SI2 and below.
• Clouds: Groups of pinpoints clustered together. Small clouds are invisible; large or dense clouds can give a stone a hazy appearance even at SI1 if they cover a large area.
• Crystals: Internal mineral crystals trapped in the diamond. Light crystals (tiny white or clear) are nearly invisible; dark crystals (black or dark brown) are much more noticeable and affect the eye-clean threshold.
• Needles: Thin, straight white crystal inclusions. Usually invisible at VS grades.
• Knots: Surface-reaching crystal inclusions. Can affect durability in extreme cases. Graded down to SI or I.
• Cavities: Small pits on the surface where a crystal was polished away. Usually at I grades.
• Laser drill holes: Microscopic channels drilled into the stone to reach and lighten dark inclusions. Treatment disclosure required on certificates.

The practical implication: when comparing two SI1 stones, the one with small white feathers near the girdle will look eye-clean while the one with a dark crystal in the center of the table may not. Always ask to see the plot diagram and high-resolution photos before paying.

Inclusion placement matters as much as grade

What you cannot see without a loupe

Always invisible to the naked eye, regardless of grade:

• Pinpoints: Microscopic crystals below roughly 0.3mm.
• Small feathers under 1mm: Thin internal fractures that are too small to catch light.
• Small clouds: Groups of pinpoints spanning less than 1mm total.
• Needles under 1mm: Thin, straight white crystals.
• Graining: Internal structural irregularities from crystal growth. Visible only under polarized light in laboratory settings.

Potentially visible to the naked eye at SI2 and below:

• Large feathers over 1mm: Catch light at the fracture interface.
• Dark crystals: Small black inclusions over 0.5mm.
• Extended clouds over 2mm: Can give the stone a hazy appearance.
• Twinning wisps in certain orientations: Extended bands from crystal growth.

Almost always visible at I1 and below:

• Chips or breaks: Surface-reaching fractures.
• Large dark crystals: Over 1mm in size.
• Large or dense clouds: Cover more than 25 percent of the table area.

When to spend more on clarity

Enhancement treatments

Some diamond sellers offer "enhanced" stones at prices below comparable untreated stones. Understanding the treatments is important:

• Laser drilling: A laser drills a thin channel to a dark inclusion to bleach or remove it. Legal with disclosure. Permanent. The stone is permanently altered; must be disclosed on grading reports.
• Fracture filling: Glass or resin injected into feathers to make them less visible. Not permanent (can be damaged by heat, ultrasonic cleaning, or jewelry repair). Legal with disclosure; must be disclosed on grading reports. Generally avoid.
• HPHT color treatment: High pressure/high temperature treatment to improve color. Legal with disclosure.
• Deep boiling: Used to remove surface stains. Considered standard processing; not a disclosed treatment.

For engagement rings, prefer untreated stones. All Diavlia diamonds are untreated; the IGI certificate confirms this.

Clarity in lab-grown vs mined

Lab-grown diamonds are graded on the same clarity scale as mined. Typical clarity distribution differs slightly:

• Lab-grown stones are typically graded between VVS2 and SI1 (most production is in this range).
• Mined stones show a broader distribution because natural formation produces more variation.
• FL and IF grades are rare in both categories.
• Lab-grown stones sometimes have metallic inclusions from the growth process (small traces of metal catalysts). These are typically microscopic and do not affect eye-clean appearance.

The practical shopping implication: lab-grown stones at VS1 to VS2 clarity are widely available at the price point where mined stones might only offer SI1 to SI2. If you prioritize clarity, lab-grown gives you more grade for the money.

FAQs

What clarity is best for an engagement ring?

VS2 for round, cushion, oval, and most brilliant-cut shapes. VS1 for emerald, asscher, and other step cuts. SI1 acceptable for budget-conscious buyers of brilliant cuts with verified favorable inclusion placement.

Is SI1 diamond clarity good?

Yes for brilliant-cut shapes. Verify the inclusion placement is favorable (no dark crystals under the table, no large feathers in the center). SI1 is the most common clarity choice for value-conscious buyers and produces eye-clean appearance in roughly 85 percent of stones.

What does "eye-clean" mean?

No inclusions visible to the naked eye at normal viewing distance (8 to 12 inches from the face). A stone can be graded SI1 or SI2 and still be eye-clean if the inclusions are small or well-placed.

Is VVS better than VS?

Technically yes at the loupe level, but the difference is invisible to the naked eye. The 20 to 35 percent price premium for VVS over VS is typically not worth it unless you specifically want the highest-tier certificate for heirloom or resale reasons.

What is the worst clarity to avoid?

I1, I2, I3. Inclusions typically visible to the naked eye and often affect the stone's brilliance. Avoid for engagement rings or any piece where appearance matters.

Can I see inclusions on an SI1 diamond?

Under 10x magnification, yes. With the naked eye at normal viewing distance, usually no, especially in brilliant-cut shapes. Always verify the specific stone is eye-clean before paying.

Does clarity affect how bright a diamond looks?

Only at the extremes. FL through SI1 stones all look equally bright because the inclusions are too small to block light meaningfully. At SI2 and below, larger inclusions can reduce brilliance by blocking or scattering light passing through the stone.

What is the plot diagram on a certificate?

A schematic drawing showing where each significant inclusion is located in the stone (top view and side view). Each inclusion type has a specific symbol (red for crystals, green for feathers, etc.). The plot tells you exactly where to look for each inclusion and is essential for evaluating SI-grade stones before buying.

Can clarity be improved after buying?

Not without treatment, which is disclosed on grading reports and typically reduces the stone's value. The specific treatments that improve apparent clarity (laser drilling, fracture filling) have trade-offs and are generally avoided for engagement rings.

How does clarity compare to color and cut in importance?

Cut is most important (affects sparkle directly). Carat and shape come next. Color matters more in white metals. Clarity is generally the easiest C to compromise on because most of the grade difference is invisible. See our full 4 Cs ranking for the complete framework.

Related reading

• The 4 C's Ranked
• Certified Diamond Buying Guide
• Diamond Fluorescence Guide
• Diamond Color: D vs E vs F vs G vs H
• Emerald Cut Guide
• Asscher Cut Guide

Last updated: April 2026.