Diamond Education Center
Everything You Need to Know
About Lab-Grown Diamonds
An honest guide to diamond quality, lab-grown science, the 4Cs, care, and certifications — written by the gemologists and designers who built Bonjoojoo.
What Are Lab-Grown Diamonds?
Lab-grown diamonds are real diamonds — not simulants, not substitutes. They are composed of pure carbon in a cubic crystal structure, chemically and physically identical to diamonds formed deep in the Earth over billions of years.
The difference is process, not product. Natural diamonds form under extreme heat and pressure 120 miles beneath the Earth's surface. Lab-grown diamonds replicate those exact conditions in a controlled environment, producing a diamond that is indistinguishable from a mined diamond — even to a trained gemologist using conventional tools.
The Federal Trade Commission (FTC) officially recognizes lab-grown diamonds as “diamonds.” The GIA and IGI — the world's leading gemological institutes — certify them with the same grading scales used for mined stones.
CVD Method (Chemical Vapor Deposition)
A thin diamond seed is placed in a sealed chamber filled with carbon-rich gas. Microwaves ionize the gas, causing carbon atoms to deposit layer by layer onto the seed, building a diamond crystal atom by atom over 6–12 weeks.
HPHT Method (High Pressure High Temperature)
A carbon source is subjected to ~1.5 million PSI of pressure and temperatures exceeding 1,400°C — replicating the deep mantle conditions where natural diamonds form. A diamond crystal grows from a seed over days to weeks.
Lab-Grown vs. Mined Diamonds
| Category | Lab-Grown Diamond | Mined Diamond |
|---|---|---|
| Chemical Composition | Pure carbon — identical to mined | Pure carbon |
| Hardness | 10 on Mohs scale | 10 on Mohs scale |
| IGI/GIA Certified | Yes | Yes |
| Brilliance & Fire | Identical | Identical |
| Conflict-Free | Guaranteed — fully traceable | Difficult to verify |
| Environmental Impact | 95% lower | High (land disruption, emissions) |
| Price vs. Mined | 60–80% less for same quality | Baseline |
| Origin Traceability | Fully traceable | Opaque supply chains |
| Resale Value | Varies — worn as jewelry, not investment | Varies — not reliably high |
* Resale value for both lab-grown and mined diamonds has historically been poor relative to retail price. We recommend buying jewelry for its beauty and meaning, not as a financial investment.
The 4 Cs of Diamond Quality
The 4 Cs — Cut, Color, Clarity, and Carat — are the universal standard for evaluating diamond quality. Understanding them helps you make the right choice for your budget and aesthetic.
Cut
The most important C
Cut refers to how well a diamond's facets interact with light — not the shape, but the precision of the angles and proportions. A well-cut diamond will sparkle brilliantly even with slightly lower color or clarity. Poor cut makes a diamond look dull regardless of other grades.
Expert tip: Never sacrifice cut grade for carat size. A well-cut 1ct looks far more impressive than a poorly cut 1.5ct.
Color
Less color = more valuable
Diamond color is graded on a D–Z scale, from colorless (D) to noticeably yellow (Z). The less color a diamond has, the rarer and more valuable it is. Most buyers can't distinguish between D, E, and F grades with the naked eye — and lab-grown diamonds often achieve higher color grades than mined diamonds at the same price point.
Expert tip: For white gold or platinum settings, choose G–H or better. For yellow gold, J–K can look beautiful and cost significantly less.
Clarity
Nature's fingerprint
Clarity measures internal characteristics (inclusions) and surface blemishes. Almost all diamonds have some, most invisible to the naked eye. The GIA clarity scale has 11 grades, and an "eye-clean" diamond — one where inclusions aren't visible without magnification — can be found well below the top grades.
Expert tip: VS2 to SI1 is the sweet spot for most buyers — indistinguishable from flawless to the naked eye, but significantly more accessible.
Carat
Weight, not size
Carat is a unit of weight (1 carat = 0.2 grams), not size. Two diamonds of the same carat weight can look very different in size depending on their cut and shape. Price per carat also increases non-linearly — a 2-carat diamond costs significantly more than twice a 1-carat diamond of equal quality.
Expert tip: Shopping just below round numbers (0.9ct instead of 1.0ct, 1.8ct instead of 2.0ct) can save significantly with no perceptible size difference.
Care & Maintenance
Lab-grown diamonds are just as durable as mined diamonds — 10 on the Mohs hardness scale. With the right care, your Bonjoojoo piece will look as beautiful in 50 years as it does today.
Daily Wear
- Safe to wear daily — diamonds are the hardest natural material
- Remove before heavy gym workouts, gardening, or contact sports
- Apply perfume, lotions, and hairspray before putting on jewelry
- Avoid swimming in chlorinated pools or saltwater
Cleaning at Home
- Warm water + a few drops of dish soap + soft toothbrush — works perfectly
- Soak for 20–30 minutes, then gently scrub around the setting
- Rinse thoroughly and pat dry with a lint-free cloth
- Ultrasonic cleaners are safe for most diamond pieces (not for emerald-cut)
Storage
- Store each piece separately — diamonds can scratch other jewelry
- Use the soft pouch and box included with every Bonjoojoo purchase
- Keep away from direct sunlight and extreme temperatures
- Anti-tarnish strips in your jewelry box help preserve metal finishes
Professional Care
- Annual inspection recommended — we'll check prongs, settings, and clasps
- Professional polishing restores luster and removes surface scratches
- Any repairs covered under our lifetime warranty
- Contact us at care@bonjoojoo.com to schedule an inspection
Certifications
Every Bonjoojoo diamond comes with a grading report from one of the world's leading independent gemological laboratories. This report is your diamond's fingerprint — it contains an exact record of its 4 Cs, dimensions, fluorescence, and identifying characteristics.
IGI Certified
International Gemological Institute
The world's largest independent jewelry certification organization. IGI was among the first institutes to develop grading standards specifically for lab-grown diamonds and is widely recognized as the gold standard for lab-grown certification.
Each IGI certificate includes a unique report number you can verify at igi.world.
GIA Certified
Gemological Institute of America
Founded in 1931, GIA invented the 4 Cs grading system and is considered the most authoritative gemological institute globally. GIA now grades lab-grown diamonds with the same precision and standards as natural diamonds.
GIA certificate numbers can be verified at gia.edu/report-check.
What's on a grading certificate?
Frequently Asked Questions
Will a lab-grown diamond lose its sparkle over time?
No. Diamond hardness is permanent — it's determined by the crystal structure, not the growing method. Your lab-grown diamond will sparkle exactly the same in 50 years as it does today, provided it's cleaned regularly.
Can a jeweler tell it's lab-grown?
Not with conventional tools. Lab-grown and mined diamonds are chemically identical, and even experienced gemologists cannot distinguish them visually. Specialized equipment can detect growth patterns, which is why we include certificates that clearly disclose lab origin — we're proud of it.
Are lab-grown diamonds graded the same way as mined diamonds?
Yes. The IGI and GIA use identical 4 Cs grading scales for both lab-grown and mined diamonds. The certificates look the same; the only difference is the origin notation.
Do lab-grown diamonds have flaws or inclusions?
They can, just like mined diamonds. The clarity grade on your certificate will tell you exactly what inclusions are present and how visible they are. Many of our diamonds are eye-clean in the VS2–SI1 range.
Why are lab-grown diamonds so much cheaper than mined ones?
Primarily because the supply chain is shorter and the input costs are lower. Mining requires enormous infrastructure, energy, and logistics. Growing a diamond in a lab doesn't. We pass those savings to you — the diamond's beauty and durability are identical.
Are all your diamonds ethically sourced?
Yes. By definition, lab-grown diamonds involve no mining, no land disruption, and no opaque supply chains. Every diamond we use has a fully traceable origin from certified producers, and all are grown using renewable-backed energy.
What shapes do you offer?
We carry Round, Oval, Cushion, Princess, Emerald, Pear, Marquise, Asscher, and Radiant cuts. Round brilliant is the most popular and tends to show the most brilliance. Fancy shapes like oval and pear can appear larger face-up for the same carat weight.
What's the best carat size for an engagement ring?
It depends entirely on personal preference and budget. The most popular range is 0.9–1.5ct for solitaire engagement rings. With lab-grown diamonds, many customers find they can go a full size up compared to what they'd spend on a mined stone.
Ready to Find Your Diamond?
Browse our full collection of IGI and GIA certified lab-grown diamond jewelry, or speak with one of our gemologists for a personalized recommendation.