Cut & certification

The 4Cs for Lab-Grown Diamonds

Our catalog fixes color (D–F), clarity (VVS2 or better) and cut (GCAL 8X), so the choices left are size and shape. Here's what each grade means.

Cut

A GCAL 8X round brilliant resting on dark stone, showing white brilliance and flashes of color
Cut decides how much light and color a diamond returns to your eye. A GCAL 8X round. Image: GCAL.

Cut decides brightness, fire and scintillation, which is what people notice at a glance. A poorly cut stone looks dull at any color or clarity.

"Excellent" alone is a broad band: GCAL says more than half of round brilliants earn it. GCAL 8X requires Excellent in all eight cut factors, which is the cut grade on every stone we sell. See what GCAL 8X certification means and Hearts & Arrows for the detail.

Color

Color is graded from D (colorless) down to Z. D, E and F are the colorless grades; from G down, a warm tint becomes easier to see, especially in larger stones and white metal settings.

Diagram of diamond color grades D through M, grouped as colorless, near colorless and faint, with Arelia's D to F range highlighted
The first ten grades of GIA's D-to-Z color scale.

Clarity

Clarity grades the size and visibility of inclusions under 10x magnification. VVS2 or better (VVS2, VVS1, IF and FL) means inclusions are very hard to find even for a grader with a loupe.

Diagram of diamond clarity grades from FL and IF through VVS, VS, SI and I, with Arelia's FL to VVS2 range highlighted
GIA's clarity scale, from Flawless to Included.

Why we stop at D–F and VVS2 or better

In lab-grown diamonds the price step from G–H color or VS clarity up to D–F and VVS is small, much smaller than in natural diamonds. So we stock only the top of both scales, plus GCAL 8X cut, and leave nothing to second-guess on those three Cs. As of November 3, 2026, our 253 loose diamonds broke down like this:

Swipe the table sideways →

ColorStonesClarityStones
D195FL6
E46IF69
F11VVS1104
G1VVS273
VS11

Carat

Carat is weight, not size. What you see is the diameter across the top, which also depends on how the stone is cut. For diameters by carat weight and how sizes compare on the hand, see how to upgrade your engagement ring diamond.

To-scale diagram of round diamond diameters: 1 carat about 6.5 mm, 1.5 carat 7.4 mm, 2 carat 8.1 mm, 2.5 carat 8.7 mm, 3 carat 9.3 mm
Round diameters to scale: medians of stones in Arelia's catalog, September 2026. Individual stones vary by a few tenths of a millimeter with their proportions.

For what each size costs today, see lab-grown diamond prices by carat.

Shape

Shape is not one of the 4Cs, but it changes how large a stone looks for its weight and how it sparkles. We stock round, oval, pear, princess, radiant, marquise and cushion; see lab-grown diamond shapes.

Every stone is GCAL 8X, D–F color and VVS2 or better. Choose the size and shape.

Shop diamonds

Keep reading

Frequently asked questions

What is the difference between D, E and F color?

All three are colorless. D is the top of the scale; E and F show only faint traces of color that a trained grader sees under controlled lighting, not something you notice in a ring.

Can you see the difference between VVS2 and Flawless?

No. VVS inclusions are very hard to find even under 10x magnification. Every clarity grade we sell looks clean to the eye.

How big is a 2 carat lab-grown diamond?

A well-cut 2 carat round measures about 8.0 to 8.1mm across. The exact diameter depends on how the stone is cut, so check the measurements on its certificate.

Do the 4Cs work the same way for lab-grown and natural diamonds?

Yes, the scales are the same. GIA stopped giving color and clarity grades to lab-grown diamonds in October 2025; GCAL certificates, like the ones on Arelia stones, still grade all four Cs.

← All Buyer's Guide topics