The diamond world has changed. For centuries, all diamonds were mined from the earth. Now, laboratory-grown diamonds—chemically identical to mined diamonds—are available, more affordable, and more sustainable.
If you're considering a diamond purchase, the choice between lab-grown and mined is more complex than price. Let's break down the real differences.
What Are Lab-Grown Diamonds?
Lab-grown diamonds (also called lab-created, synthetic, or cultured diamonds) are diamonds created in a laboratory, not mined from the earth.
How they're made:
Two primary methods exist:
HPHT (High Pressure, High Temperature): Mimics the natural process. A diamond seed is subjected to extreme pressure (1.5 million PSI) and temperature (1,500°C) in a specialized chamber. Carbon dissolves and recrystallizes on the seed, forming a diamond. Takes 1–3 weeks.
CVD (Chemical Vapor Deposition): A diamond seed is placed in a chamber with carbon-rich gases. Plasma heats the gases, causing carbon atoms to deposit layer-by-layer on the seed. Takes 3–4 weeks. Results in fewer inclusions (higher clarity potential).
The chemistry: The result is a diamond. Not a diamond-like substance. Not a substitute. An actual diamond—carbon atoms arranged in a crystal lattice, with the same refractive index, hardness, and optical properties as a mined diamond.
Lab-Grown vs Mined: The Core Differences
Chemical and Physical Properties
| Property | Lab-Grown | Mined |
|---|---|---|
| Hardness | 10 (Mohs scale) | 10 (Mohs scale) |
| Refractive Index | 2.42 | 2.42 |
| Specific Gravity | 3.52 | 3.52 |
| Thermal Conductivity | Identical | Identical |
| Chemical Composition | Carbon (pure) | Carbon (pure) |
Bottom line: Chemically and physically, they're identical. A diamond tester cannot distinguish them. Only advanced laboratory equipment (like spectroscopy or photoluminescence testing) can determine origin.
Origin
Lab-grown: Created in a lab in weeks. Origin is documented and traceable. You know exactly where and when it was made.
Mined: Formed in the earth over 1–3 billion years. Origin in a specific mine, but often poorly documented, especially for older stones. Conflict diamonds (mined in war zones) are a historical concern, though modern certification systems (Kimberley Process, though flawed) attempt to address this.
Time to Formation
Lab-grown: 1–4 weeks in the lab.
Mined: 1–3 billion years in the earth.
Some argue mined diamonds have "rarity and history." Others argue lab-grown diamonds are more sustainable and modern. Neither argument changes the diamond's physical properties.
Price
Lab-grown: 40–60% cheaper than comparable mined diamonds.
Why: Manufacturing costs are lower than mining costs. A mined 1-carat, G colour, VS1 clarity, Excellent cut diamond might cost R12,000–R15,000. A lab-grown identical diamond might cost R5,000–R8,000.
Environmental Impact
Lab-grown:
- Require significant electricity (100–200 kWh per carat for HPHT; less for CVD)
- In regions with renewable energy, impact is minimal
- No mining, so no mining-related environmental damage (habitat destruction, water use, chemical pollution)
- Smaller carbon footprint overall
Mined:
- Extensive mining operations (open-pit or underground)
- Large water consumption
- Chemical pollution (tailings, processing chemicals)
- Habitat disruption
- High carbon footprint from machinery, transport, and processing
Winner: Lab-grown, especially if made with renewable energy.
Sustainability and Ethics
Lab-grown:
- No conflict diamonds (diamonds mined in war zones)
- Supply chain is transparent and traceable
- Workers are in controlled laboratory environments
- More ethical from a human rights perspective
Mined:
- Risk of conflict diamonds (though modern certification systems attempt prevention)
- Mining can fund violence in unstable regions
- Working conditions in some mines are poor
- Supply chain opacity can hide human rights issues
Winner: Lab-grown by a significant margin.
Resale Value
Lab-grown: Resale value is 50–70% lower than mined diamonds. You can't easily resell them to jewellers who deal primarily in mined diamonds. The secondary market is developing but still limited.
Mined: Strong resale market. Jewellers will buy back or consign mined diamonds. Resale value is typically 50–60% of purchase price (depending on market conditions).
Important: If you think you might resell the diamond in future, mined is the safer choice. If you're buying to keep, lab-grown's price advantage might outweigh resale concerns.
Detectability
Can you tell the difference?
To the naked eye: No. Lab-grown and mined diamonds look identical.
With a diamond tester: No. Both conduct heat in the same way.
Under magnification: Maybe. Lab-grown may show different inclusion patterns (CVD diamonds often have fewer inclusions). But this isn't foolproof.
With advanced lab equipment: Yes. Spectroscopy, photoluminescence, or other specialized equipment can reveal origin. But this requires professional testing.
Important disclosure: Any seller should disclose whether a diamond is lab-grown. If you're buying lab-grown, insist on documentation. If you're buying mined, insist the seller states it's natural/mined.
Should You Buy Lab-Grown or Mined?
Choose Lab-Grown If:
- Budget is a priority: You want a larger or higher-quality diamond for less money
- Ethics matter: You want a transparent supply chain and sustainable origin
- You won't resell: You're keeping the diamond as an engagement ring or heirloom
- Environmental impact is important: You prefer lower carbon footprint
- You want exclusivity: Lab-grown is still relatively rare (10–15% of diamond market), so it's distinctive
Choose Mined If:
- Resale is important: You might sell or trade the diamond later
- You prefer tradition: Mined diamonds feel "classic" to many people
- Geological rarity appeals: The diamond formed over a billion years—that story matters to you
- Collectibility matters: Mined diamonds are more collectible and established in the market
- You want maximum investment potential: Mined diamonds have stronger long-term value
Grading Lab-Grown Diamonds
Lab-grown diamonds are graded by the same labs (GIA, HRD, AGS) using the same criteria as mined diamonds.
The four Cs apply identically:
- Carat: Weight measured the same way
- Colour: Graded D–Z, same scale as mined
- Clarity: Graded FL–I3, same scale as mined
- Cut: Graded Excellent–Poor, same standard as mined
One difference: The report will state "Lab-Grown Diamond" or "Laboratory-Created Diamond" on the certificate. This is mandatory disclosure.
Note: Some sellers use non-standard labs or no certification for lab-grown diamonds. Always insist on a GIA, HRD, or AGS report.
The Price Comparison: Real Numbers
1-carat diamond, G colour (near-colourless), VS1 clarity (eye-clean), Excellent cut:
Mined diamond: R12,000–R16,000
Lab-grown diamond: R5,000–R8,000
Savings: 50–60%
2-carat comparison:
Mined: R28,000–R35,000
Lab-grown: R10,000–R15,000
Savings: 55–65%
The larger the diamond, the greater the absolute savings. Lab-grown makes the biggest difference for larger stones (2+ carats).
Frequently Asked Questions
Q: Are lab-grown diamonds real diamonds?
A: Yes. They're chemically and optically identical to mined diamonds. The only difference is origin.
Q: Will a lab-grown diamond hold value?
A: Not as well as mined. Resale value is 50–70% lower. But if you're keeping it forever, resale value is irrelevant.
Q: Can I tell if a diamond is lab-grown by looking at it?
A: No. You need a professional lab test (advanced equipment, not just a basic diamond tester).
Q: Is lab-grown diamond production environmentally worse than mining?
A: No. Even accounting for electricity use, lab-grown has a lower environmental impact than mining when the electricity comes from any mix of sources. If powered by renewables, the advantage is clear.
Q: Should I disclose if my diamond is lab-grown?
A: Yes, always. Responsible sellers disclose origin. If buying, insist on disclosure.
Q: Can lab-grown diamonds be insured the same way?
A: Yes. They're insured like any diamond. But inform your insurer of the lab-grown origin (some may adjust appraisals slightly).
Q: Are lab-grown diamonds certified?
A: High-quality ones are. Insist on a GIA, HRD, or AGS certificate.
Q: Will lab-grown diamonds become cheaper over time?
A: Likely. As production scales, costs will decrease further. If price is your only consideration, waiting might be wise. But current pricing is already very favorable.
Q: Can you mix lab-grown and mined diamonds in one setting?
A: Yes. A lab-grown solitaire with mined diamond accents, for example. Just be transparent about it.
Q: Will lab-grown diamonds ever be more valuable than mined?
A: Unlikely. The rarity and history of mined diamonds—formed over billions of years—gives them inherent collectibility. Lab-grown may become more valuable in absolute terms, but relative to mined, probably not.
Q: Is buying lab-grown ethically better?
A: From a sustainability and conflict-free perspective, yes. From a cultural perspective, depends on who you ask. Mined diamonds are traditional; lab-grown is modern. Choose based on your values.
The Bottom Line
Lab-grown diamonds are real diamonds—chemically identical, optically identical, physically identical to mined diamonds. The difference is origin and price.
If you want to maximize budget, minimize environmental impact, and keep the diamond forever, lab-grown is an excellent choice. If you value tradition, collectibility, and potential resale, mined is the classic option.
Neither is "better." It depends on your priorities.
At Pura, we source both lab-grown and mined diamonds. We'll explain the trade-offs and help you choose the right option for your needs.
Want to compare options? Come in, and we'll show you lab-grown and mined diamonds side-by-side. You'll see the difference in price—and no difference in beauty.