The complete guide
How to read a diamond.
Four grades decide what a diamond looks like and what it costs — cut, color, clarity and carat. Here is what each one actually means on a hand, which ones are worth paying for, and which ones quietly don't matter.
01 · Cut
The only C you can see across a room.
Cut is not the shape — it is the geometry: how precisely the facets are angled and proportioned. Cut too deep or too shallow and light leaks out the sides or the bottom instead of returning to your eye. A perfectly cut stone of modest color and clarity will out-sparkle a flawless stone with a mediocre cut, every time. It is the grade to protect first.
Ideal / Excellent
Worth paying for
Very Good
Good
Fair
Poor
02 · Color
Graded D to Z — the less, the better.
The color scale measures the absence of color: D is icy, Z is visibly warm. The scale was designed for grading trays and side-by-side comparison — on a hand, set in metal, the difference between D and G is close to invisible. Yellow gold settings even flatter a touch of warmth. Whatever letter your stone is, we will tell you — ask us for the grade before you buy.
03 · Clarity
Nature's fingerprints, under 10× magnification.
Clarity grades count the tiny internal characteristics — inclusions — visible under a jeweler's loupe. The scale runs from Flawless down to Included. Here is the honest part: everything from VS2 upward is eye-clean — at reading distance you will never see a thing. Paying for FL is paying for a certificate line, not a visible difference — so spend it on carat or cut instead.
Gold marks the eye-clean range — no loupe required.
04 · Carat
Weight — not size, and priced on a curve.
A carat is 0.2 grams of diamond. Two things surprise people. First, face-up size grows slower than weight — a 2.00ct round looks nowhere near twice as big as a 1.00ct. Elongated shapes like oval and marquise face up larger per carat. Second, price does not grow in a straight line: our engine prices the stone roughly with weight to the power 1.65, so a 2ct costs about three times a 1ct — that curve is on every product page, live, as you change the carat.
Beyond the 4Cs
The fine print that isn't fine.
Polish & symmetry
How finely the facets are finished and how precisely they mirror each other. Graded Excellent to Poor; both quietly affect sparkle, and both sit on the report.
Fluorescence
A soft glow under UV light, graded None to Very Strong. None-to-Faint is invisible in daily life. Ask us for the grade on any piece and we will send it.
Certification
An independent IGI report records every grade on this page. Selected Auvi pieces are IGI certified — where a piece is, that is stated on its product page, and the paperwork travels with it.
Eye-clean
The only clarity question that matters in real life: can you see anything at reading distance? VVS and VS stones are eye-clean by a wide margin.
If you remember one thing
Spend in this order.
- 1 Cut — never compromise; it is all of the sparkle
- 2 Clarity — eye-clean is the finish line (VS2+); beyond that is paperwork
- 3 Color — near-colorless (D–G) reads icy on every hand
- 4 Carat — whatever the budget still allows, guilt-free
Quick answers
Grading, asked plainly.
Rarely, once it is set. Side by side on a grading tray, D and G read differently to a trained eye; on a hand, in a setting, in real light, nearly nobody can tell. G–F is the sweet spot for value — icy white without the collector premium.
A well-placed VS2 or VS1. SI stones can be eye-clean bargains, but it depends entirely on where the inclusions sit — and you cannot tell from a grade alone. VS clarity removes the gamble. Tell us your budget and we will be straight with you about where it lands.
Because cut is the only C you can see from across the room. A perfectly cut G/VS2 will out-sparkle a poorly cut D/IF every single time — proportions decide how much light returns to your eye, and no color or clarity grade can compensate for light leaking out the bottom.
Identically. Labs grade lab-grown stones on the same 4C scales, with the same instruments and the same standards — the growth method is noted on the report, and nothing else changes.