A lab-grown diamond color and clarity chart follows the same grading scales as natural diamonds: color runs D (colorless) to Z (light yellow), clarity runs FL (flawless) to I (included), and cut runs Excellent to Poor. For wholesale resale, most jewelers stock the colorless-to-near-colorless, eye-clean, Excellent-cut sweet spot, where value and visual quality meet.

Lab-Grown Diamond Color, Clarity & Cut Chart for Wholesale Buyers (2026)

If you buy diamonds for resale, the 4Cs are not abstract gemology — they are your purchase order. Every stone you stock is a decision about which color, clarity, cut, and carat combination will sell at your price point and still leave margin. This is a buyer's reference: the standard GIA/IGI grading scales laid out as clean charts, plus practical notes on which grade combinations make sense to stock for resale and why.

Lab-grown diamonds are graded on exactly the same scales as mined diamonds — a lab report does not use a softer ruler. A G-color VS1 lab-grown stone is graded against the same criteria as a G VS1 natural. What follows is the chart a buying desk actually uses, written for a wholesale buyer choosing what to put in the case.

How is lab-grown diamond color graded?

Color grades a diamond by the absence of color. The scale starts at D — the most colorless — and runs down to Z, where a faint yellow or brown tint becomes visible to the eye. The less color, the rarer and (usually) the more expensive the stone. Grading is done face-down against a master set under controlled light.

Practical read for the case: D–F carries a colorless premium most resale customers do not need; G–J (near-colorless) is where the bulk of wholesale demand sits, because the stone reads white to the eye at a lower cost. For platinum or white-gold settings, buyers often lean G–H to keep the stone visibly white against a white metal; in yellow or rose gold, I–J faces up beautifully and stretches the budget, since the warm metal masks the faint warmth.

How is lab-grown diamond clarity graded?

Clarity grades the internal inclusions and surface blemishes in a stone, assessed under 10x magnification. The fewer and less visible the inclusions, the higher the grade. The scale below is the full GIA/IGI clarity ladder.

The term that matters most for resale is eye-clean — no inclusions visible to the naked eye at normal viewing distance. A buyer does not need to pay for FL/IF perfection to deliver an eye-clean stone. VS1–VS2 is reliably eye-clean across shapes and sizes, and many SI1 stones are eye-clean too, especially in smaller carats and brilliant cuts where inclusions hide in the faceting. The trap is at SI2 and below: clean for some stones, visibly included in others, which is why those grades have to be reviewed stone by stone rather than bought blind off a list.

How is lab-grown diamond cut graded?

Cut is the C that does the most visible work and the one buyers most often underweight. It grades how well a stone's proportions, symmetry, and polish return light — its sparkle. A poorly cut D-Flawless stone can look duller than a well-cut G VS2. On round brilliants, cut is graded on a five-step scale; fancy shapes (oval, emerald, pear, etc.) are typically described by polish and symmetry rather than an overall cut grade, so those you judge by eye and proportion.

For round brilliants, do not compromise on cut. Excellent (and where offered, Ideal) cut is the cheapest way to make a stone look more expensive than its color and clarity grades suggest. On fancy shapes, look at the report's polish and symmetry grades and judge the outline, depth, and any bow-tie effect by eye, because two stones with identical 4Cs can face up very differently.

Where does carat fit in?

Carat is weight, not size, and it interacts with the other three Cs and with price more sharply than buyers expect. Prices step up at the round "magic" weights — 0.50, 1.00, 1.50, 2.00 ct — where demand clusters. A stone that grades 0.90 ct can cost meaningfully less per carat than a 1.00 ct of the same color, clarity, and cut, while facing up nearly as large. For a resale program, buying just under a magic weight (a 0.90 instead of a 1.00, a 1.90 instead of a 2.00) is a standard way to protect margin without a visible drop in size.

What grade combination should you stock for resale?

There is no single "best" stone — there is the best stone for a price point. But across most wholesale programs the value sweet spot clusters in a predictable band. Here is how the grades combine in practice.

For most jewelers, the middle row is the workhorse: a G or H color, VS1–VS2 clarity, Excellent-cut round (or a well-cut fancy of the same grades) is eye-clean, faces up white, and lands at a price your retail customer can sell. Reserve D–F VVS for the top of the case where the customer is paying for the spec on the report, and use I–J SI1 — verified eye-clean — to hit aggressive price points, especially in warm metals. Whatever the tier, confirm color and clarity against an IGI (sometimes GIA) report, and verify the report number on the lab's database.

How do lab-grown grades affect wholesale pricing?

Within lab-grown, the grade ladder still drives price: a D VVS1 costs more than a G VS2, which costs more than a J SI1, all else equal. But because lab-grown diamonds are priced per supplier rather than off the Rapaport sheet, the spread between grades and the absolute level both move with manufacturing cost. A supplier that grows and cuts its own goods — Guru Diam runs CVD production — can price closer to cost across the grade range than a reseller adding a layer. The buying move is to compare like-for-like: same shape, carat, color, clarity, cut, and lab, then compare landed cost. See our guides on the best quality lab-grown diamonds to stock and how to buy lab-grown diamonds wholesale.

Reading the report: what to verify

The chart only helps if the grades on the report are real. Every certified stone ships with an independent lab report — most commonly IGI, sometimes GIA — that states the stone is laboratory-grown and lists its 4Cs. Match the report number to the lab's online database, confirm the report says "Laboratory-Grown" (or "Lab-Grown Diamond"), and check that the stone in hand matches the report's measurements and grades. For a walkthrough, see how to read an IGI/GIA diamond certificate and GIA vs IGI certified lab-grown diamonds.

Ready to put the chart to work? Open a trade account and we will send the current loose-diamond list the same day, or browse certified lab-grown diamonds by color, clarity, cut, and carat to build your program.

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