Diamond Education · The Science of Brilliance

Know your
diamond. Don Key · Education

Everything you need to understand lab-grown diamonds — the 4 Cs, how light works inside a stone, shapes, certifications, and what makes ours different.

Diamond Education — Don Key
The Science of Brilliance
Diamond close-up
Real Diamond — Certified · Lab Grown

What You Need to Know — Lab-Grown Diamonds

A real diamond
by every measure.

Lab-grown diamonds are not simulants, fakes, or imitations. They are real diamonds — grown using the same carbon crystallization process that happens deep within the earth, just replicated in a controlled environment in weeks rather than millions of years.

Every property that defines a diamond — hardness of 10 on the Mohs scale, refractive index of 2.417, identical chemical composition of pure carbon — is present in every stone we sell. The only difference is origin, and that origin makes them conflict-free, traceable, and 60–80% more accessible.

Learn the 4 Cs

The 4 Cs — Interactive Guide

The universal
language of diamonds.

Every diamond — mined or lab-grown — is evaluated on the same four criteria. Here's what each one means, and where we set the bar.

Cut — The engine of sparkle.

Cut is the most critical of the 4 Cs — and the only one entirely controlled by human craftsmanship. It refers not to the shape of the diamond, but to how precisely its facets are angled to interact with light. A perfectly cut diamond returns light directly back to your eye. A poorly cut one loses it through the bottom or sides, appearing dull even if flawless in every other way.

Cut is graded from Excellent to Poor. We only source Excellent and Ideal cut stones — the top tier — because no amount of clarity or color compensates for a diamond that doesn't come alive in light.

Don Key Recommendation Excellent or Ideal cut only. This is non-negotiable for us. A great cut transforms a good stone into something breathtaking.
Cut Grade Scale
Excellent
Don Key ◆
Ideal
Don Key ◆
Very Good
Acceptable
Good
Value-driven
Fair
Noticeably dull
Poor
Avoid

Color — The spectrum of purity.

Diamond color is graded on a scale from D (completely colorless) to Z (light yellow or brown tint). Paradoxically, "no color" is the ideal — a truly colorless diamond acts as a perfect prism, splitting white light into its spectral colors for maximum fire and brilliance.

The difference between D and F is invisible to the naked eye. The difference between D and J becomes noticeable in side-by-side comparison. For our stud designs, we typically recommend D–F for the crispest, most icy look, or G–H for exceptional value that still appears colorless when set.

Don Key Recommendation D–F for a crisp, colorless look. G–H for outstanding value without visible compromise.
Color Grade Scale (GIA / IGI)
D–F
Don Key ◆
G–H
Don Key ◆
I–J
Near Colorless
K–M
Faint tint
N–Z
Visible color

Clarity — Internal perfection.

Diamonds — whether from the earth or a lab — develop tiny internal characteristics called inclusions (internal) and blemishes (surface) during formation. Clarity grades measure how visible these are under 10x magnification. Most inclusions are completely invisible to the naked eye, which is why clarity is the 4 C where smart buyers find the most value.

VS1–VS2 (Very Slightly Included) is our recommended sweet spot: inclusions exist but are microscopic and invisible without magnification — yet the price difference from VVS grades is significant. FL and IF stones are beautiful, but the premium rarely justifies itself for everyday wear.

Don Key Recommendation VS1–VS2 for the ideal value-to-beauty ratio. VVS for gifts and heirlooms. Avoid SI2 and below for studs — inclusions may be visible.
Clarity Grade Scale
FL / IF
Flawless
VVS1–2
Very Very Slight
VS1–2
Don Key ◆
SI1
Slightly Incl.
SI2
May be visible
I1–3
Avoid

Carat — The measure of weight.

Carat is a unit of weight, not size. One carat equals 0.2 grams. Because density varies by shape and cut proportions, two diamonds of equal carat weight can look very different in physical size — a well-cut round brilliant will appear larger face-up than a poorly proportioned stone of the same weight.

This is where lab-grown diamonds create a genuine opportunity. Because the production process is far more efficient than mining, a 2.0ct lab-grown stone is accessible at the price point of a much smaller mined diamond. You're not compromising on quality — you're simply removing the scarcity premium.

Don Key Recommendation For studs, 0.5–1.0ct total weight (0.25–0.50ct per ear) is the classic everyday size. Lab-grown lets you go larger for the same investment.
Carat Weight — Visual Size Guide (Round Brilliant)
0.25ct
~4.1mm diameter
0.50ct
Don Key ◆
0.75ct
Don Key ◆
1.00ct
~6.5mm diameter
1.50ct
~7.4mm diameter
2.00ct
~8.2mm diameter

How Cut Affects Light — The Physics

Light in.
Brilliance out.

A diamond's cut determines how light travels through it. In an ideal cut, light enters the top (table), bounces off the angled facets (pavilion), and returns directly back through the top to your eye — creating that signature blaze of brilliance and fire.

When a diamond is cut too deep, light leaks out the side. When cut too shallow, it escapes through the bottom. Both look dull regardless of clarity or color grade — which is why cut is always our first priority.

The diagram shows how the same light behaves differently in three cut scenarios. Use the toggle to compare.

IDEAL CUT Brilliance returns ◆ Light in 100% light returned MAXIMUM BRILLIANCE

Shape Guide — Finding Yours

Every shape tells
a different story.

Shape is personal — it speaks to your aesthetic, your hand, and how you want to be seen. Here's the full guide.

Oval
An elongated round that creates a lengthening illusion on the finger. Near-identical brilliance to round, with a more distinctive silhouette.
Elongating Effect
Emerald
Step-cut with long, parallel facets that create a hall-of-mirrors effect. Emphasizes clarity and gives a vintage, editorial look.
Clarity Showcase
Cushion
Soft rounded corners on a square or rectangular body. Romantic and antique in feel, with exceptional fire and warmth.
Romantic & Soft
Princess
Square-cut with brilliant faceting — sharp corners and modern geometry. High brilliance in a contemporary silhouette.
Modern & Bold
Pear
A teardrop silhouette that combines round brilliance with a tapered point. Distinctive, elongating, and undeniably graceful.
Distinctive
Radiant
Brilliant faceting in a rectangular or square silhouette with trimmed corners. Maximizes fire while offering a more geometric presence.
Fire & Geometry
Marquise
An elongated eye shape with pointed ends that creates maximum finger coverage for its carat weight. Dramatic and vintage in character.
Maximum Coverage

Lab-Grown vs. Mined — The Truth

Same diamond.
Better origin.

Lab-grown diamonds are not simulants, not cubic zirconia, not moissanite. Every measurable property is identical to mined. Here's the full side-by-side.

Property Lab-Grown (Don Key) Mined (Earth)
Chemical Composition Pure carbon (C) Identical Pure carbon (C)
Hardness (Mohs Scale) 10 — Hardest known Identical 10 — Hardest known
Refractive Index 2.417 Identical 2.417
Thermal Conductivity 900–2,320 W/(m·K) Identical 900–2,320 W/(m·K)
Certification IGI / GIA certified Traceable GIA / AGS certified
Origin Conflict-free by design Ethical Often uncertain
Environmental Impact ~90% lower carbon footprint Planet-first Significant land & water use
Land Disruption None Zero impact ~250 tons of earth per carat
Price vs. Mined Equivalent 60–80% more accessible Better value Premium scarcity pricing
Detectable Difference Only by specialist equipment Only by specialist equipment

Certification — Your Diamond's DNA

Every stone comes
with proof.

A diamond certificate is the independent, third-party documentation of your stone's exact characteristics — its 4 Cs grades, dimensions, and lab-grown status. It's the only way to know for certain what you're buying.

  • IGI
    International Gemological Institute The world's largest independent lab for lab-grown diamonds. certification is the global benchmark — our primary certificate on every stone over 0.25ct. Every grade is documented: cut, color, clarity, carat, measurements, and lab-grown origin.
  • GIA
    Gemological Institute of America The organization that created the modern 4 Cs grading system. GIA certification is available on select Don Key stones on request — their lab-grown grading reports carry enormous industry weight.
  • CVD
    Chemical Vapor Deposition — The Method Our diamonds are grown via CVD — carbon gas is ionized in a controlled chamber, depositing atom by atom onto a seed crystal. The certificate documents this method, providing complete traceability from growth to your setting.
Shop
IGI Diamond Certificate
Certified · Every Stone

Glossary — Key Terms

The words
that matter.

A quick reference for the terminology you'll encounter when shopping for diamonds — demystified.

Brilliance

The white light reflected from the interior and surface of a diamond. Maximized by an excellent cut.

Fire

The dispersion of white light into spectral colors — the rainbow flashes you see inside a moving diamond.

Scintillation

The pattern of light and dark areas — sparkle — as a diamond or viewer moves. The "life" of the stone.

Fluorescence

The glow some diamonds emit under UV light. Can make D–F stones appear milky. We prefer None or Faint.

Table

The flat top facet of a diamond — the largest facet and the main window for light entry.

Pavilion

The lower, pointed portion of a diamond below the girdle. The angle of the pavilion facets determines how light bounces and exits.

Girdle

The narrow band around the widest part of the diamond that separates the crown from the pavilion.

Inclusion

An internal characteristic — crystal, feather, cloud — formed during growth. Graded under 10x magnification.

Eye-Clean

A diamond with no inclusions visible to the naked eye at 10–12 inches. VS2 and better are typically eye-clean.

CVD

Chemical Vapor Deposition — the process used to grow our diamonds. Carbon atoms deposit onto a seed crystal in a controlled gas chamber.

Point

One-hundredth of a carat. A 0.50ct diamond equals 50 points.

Simulant

A stone that looks like a diamond but is not — such as moissanite or cubic zirconia. Lab-grown diamonds are not simulants.

"Understanding a diamond is the first step in choosing one that actually means something."

Don Key · Diamond Education

Don Key Diamond Studs

Ready to Choose — Shop the Collection

Now that you
know — shop with confidence.

Every Don Key stud cab be certified, Excellent cut, set in 14K solid gold, and grown without mining a single gram of earth. The knowledge is yours. The stone is waiting.