01
Carat
The weight of the diamond — 1 carat equals 200 milligrams. Two diamonds of the same carat can look very different depending on their cut and shape.
Tip: A well-cut 0.90ct stone often appears larger than a poorly cut 1.00ct stone.
Diamond education
Know what you're buying.
A plain-English guide to the 4Cs, shapes, and certifications that define every Stone Theory diamond.
Chapter 01
The 4Cs
Carat, Color, Clarity, and Cut are the four objective measures that define a diamond's quality and value. Understand these, and you can read any certificate.
02
Color
Graded D (absolutely colorless) through Z (light yellow). Most customers are happiest in the G–H range — near-colorless with significant value over D.
Tip: Yellow-gold settings mask slight warmth, so H–J can look perfect mounted.
03
Clarity
Ranges from Flawless (FL) down to Included (I). VS1–VS2 stones are "eye-clean" — inclusions only visible under 10× magnification.
Tip: Clarity above VS2 rarely affects how the diamond looks to the naked eye.
04
Cut
How well the diamond's proportions reflect light. Rated Poor to Excellent (or Ideal). Cut has the biggest impact on brilliance — prioritize it over size.
Tip: Don't compromise on cut. An Excellent-cut 1ct will outshine a Good-cut 1.5ct every time.
Chapter 02
Diamond shapes
Each cut tells a different story. Round brilliants sparkle like fireworks; emeralds have the quiet elegance of a staircase of light. Here are the ten shapes we carry.
Round
The classic brilliant cut. Maximum sparkle, timeless appeal.
Oval
Elongates the finger. All the fire of a round, with a softer silhouette.
Cushion
Square with rounded corners. Vintage warmth, modern brilliance.
Emerald
Step-cut facets. Elegant, restrained, architectural.
Pear
Teardrop-shaped. Flattering, romantic, distinctive.
Princess
Sharp square outline. Contemporary, striking.
Radiant
Rectangular with brilliant facets. Fire of a round, shape of an emerald.
Marquise
Pointed oval. Regal, elongating, rare.
Asscher
Square step-cut. Art Deco's signature shape.
Heart
The ultimate symbol of love.
Chapter 03
Independent certification
Every Stone Theory diamond is graded by an independent laboratory. The certificate is your receipt of quality — nobody can fudge it.
GIA
Gemological Institute of America
Founded in 1931, GIA set the 4C grading standard used worldwide. The most rigorous and conservative grading body.
IGI
International Gemological Institute
The largest independent gemological laboratory. Trusted worldwide for consistent, precise grading of lab-grown diamonds.
Every certificate we issue is included with your purchase and linked from your order page. You can verify any of them directly with the issuing lab.
Chapter 04
Our diamonds
Stone Theory sells exclusively lab-grown diamonds — chemically, physically, and optically identical to mined diamonds, but with cleaner origins and a price that lets you wear something extraordinary.
Why lab-grown
- Identical to mined diamonds at the atomic level — same hardness, same fire, same brilliance
- Grown in weeks under controlled conditions, not extracted from the earth
- Significantly more accessible at the same spec, so you can choose a larger or higher-grade stone
- Zero mining impact and a transparent, traceable supply chain
- Independently graded by IGI or GIA on the same 4C scale used for mined diamonds
Every Stone Theory diamond ships with its independent grading report and a unique laser-inscribed serial number you can verify directly with the issuing lab.