Diamond Clarity Explained: From Flawless to Included

Every natural diamond formed deep in the earth, and almost every one carries tiny traces of that journey — internal marks called inclusions and surface marks called blemishes. Clarity is the grade that describes how few of those a diamond has, and it can quietly move the price by thousands. Here’s how the scale works and where the smart money sits.

What clarity actually measures

Clarity grades a diamond by the number, size, position, and visibility of its internal and external characteristics, all viewed under 10x magnification by a trained grader. The key phrase is under magnification: most inclusions that lower a grade are invisible to the naked eye. A diamond with no eye-visible flaws is called eye-clean, and that — not perfection — is what most buyers actually want.

The clarity scale, grade by grade

• FL / IF (Flawless / Internally Flawless) — no inclusions visible at 10x. Extremely rare and priced accordingly.
• VVS1 / VVS2 (Very, Very Slightly Included) — inclusions so tiny they’re hard for even experts to find. A luxury-level grade.
• VS1 / VS2 (Very Slightly Included) — minor inclusions that take effort to spot at 10x and are invisible to the eye. The value sweet spot.
• SI1 / SI2 (Slightly Included) — inclusions easily seen at 10x; SI1 is usually still eye-clean, SI2 sometimes isn’t.
• I1 / I2 / I3 (Included) — inclusions visible to the naked eye that can affect sparkle and, at the low end, durability.

A diamond doesn’t have to be flawless to look flawless. The trick is finding the lowest grade that’s still eye-clean — you pay far less for flaws no one will ever see.

Where to spend and where to save

For most people, VS1–VS2 and often a well-chosen SI1 look identical to a VVS or Flawless stone once set in a ring — but cost dramatically less. Paying for FL or IF is mostly paying for rarity you can’t see. Save on clarity, and put the money toward cut, which is what actually makes a diamond sparkle.

Size and shape change the rules

The bigger the diamond, the more clarity matters: inclusions are easier to spot in a large stone, so a 3-carat diamond needs a higher grade to stay eye-clean than a 0.5-carat one. Shape matters too. Emerald and Asscher cuts have large, open “step” facets that hide nothing, so they reward a higher clarity grade, while brilliant cuts like round and princess scatter light and mask small inclusions.

How to read clarity on a report

A grading report from a lab like GIA lists the clarity grade and usually includes a plot — a diagram mapping each inclusion’s type and location. Use it to check where the flaws sit: an inclusion near the edge can be hidden by a setting, while one dead-center under the table is more visible. The same grade can wear very differently depending on placement.

Scale

FL (flawless) to I3 (included)

Graded at

10x magnification

Best value

VS1–VS2, sometimes eye-clean SI1

Needs higher grade

Large stones, emerald & Asscher cuts

Goal

Eye-clean, not flawless

The takeaway

Clarity is one of the easiest of the 4 Cs to overpay for, because most of what it measures is invisible without a loupe. Aim for an eye-clean stone — usually VS or a carefully chosen SI1 — check the plot for where the inclusions sit, and spend the difference on a great cut. You’ll get a diamond that looks flawless to everyone but the lab, for a lot less money.

At a glance

GIA clarity scale

Grade	Meaning	Visible to the naked eye?
FL / IF	Flawless / Internally Flawless	No
VVS1, VVS2	Very, very slightly included	No — hard to see even at 10×
VS1, VS2	Very slightly included	Almost never
SI1, SI2	Slightly included	Sometimes, especially in large or step-cut stones
I1, I2, I3	Included	Usually; can affect durability

Frequently asked questions

What does eye-clean mean?

A diamond is eye-clean when no inclusion is visible face-up to the unaided eye at normal viewing distance. It is not a lab grade, so check images or view the stone yourself.

Is SI1 clarity good?

Often, yes. Many SI1 rounds under about 1.5 carats are eye-clean and cost much less than VS grades. Check where the inclusion sits and what it is — a dark crystal under the table is worse than a white feather near the edge.

Does clarity matter more for emerald and Asscher cuts?

Yes. Step cuts have large open facets that act like windows, so inclusions show more easily. Many buyers go to VS2 or better for those shapes.

Can inclusions make a diamond break?

Rarely, but large feathers that reach the surface — especially near a prong or the girdle — can weaken a stone. I-grade diamonds carry the most risk.

Sources and further reading

1. Diamond Clarity — GIA
2. The 4Cs of Diamond Quality — GIA (Gemological Institute of America)
3. Diamond clarity — Wikipedia

Links checked September 14, 2026.