Lab-grown Diamond Guide
Over the past 10 years, lab-grown diamonds have grown in popularity as an affordable alternative to natural diamonds. They can match the sparkle of natural stones, yet many consider them less rare and less precious. Here’s what makes them similar—and where they differ.
What is a lab-grown diamond?
Laboratory-grown diamonds (synthetic diamonds) are created much in the same way as natural gems, only the process is accelerated in controlled conditions. Mass production has lowered prices; some feel they lack the rarity and emotional value of naturally formed stones.
How do you grow diamonds in a lab?
Two primary processes are used:
- Chemical Vapour Deposition (CVD) — a high-quality “seed” is placed in a vacuum chamber with carbon-rich gases, heated to ~700–900°C so carbon deposits grow diamond crystals on the seed.
- High-Pressure, High-Temperature (HPHT) — a diamond seed is subjected to extreme pressure and heat to grow crystals.
The rough is then cut and polished. In theory, there’s no fixed limit to size or quantity.
Are lab-growns cheaper?
Lab-grown diamonds generally have decreasing long-term value compared to rarer natural stones.
| 1 ct, G colour, Excellent cut, VS2, Round Natural diamond | 1 ct, G colour, Excellent cut, VS2, Round Lab-grown diamond | |
|---|---|---|
| Chemical composition | C | C |
| Crystalline structure | Cubic | Cubic |
| Refractive index | 2.42 | 2.42 |
| Dispersion | 0.044 | 0.044 |
| Hardness | 10 | 10 |
| Density | 3.52 | 3.52 |
| Energy use | Around 57 kWh | Around 26 kWh |
| Scarcity | Very scarce (high quality) | No real scarcity |
| Long-term value | Stable | Decreasing |
| Average price | £4450 | £1530 |
Are lab-grown diamonds more ethical?
The sustainability picture is mixed. Production can require significant energy and often uses non-renewables. Some reports suggest higher average emissions than mined diamonds; note that methodologies and sponsorship of such studies vary.
Impacts depend on energy sources, machinery, and country of origin. Beyond environment, sustainability includes livelihoods—natural diamond economies (e.g., Botswana) have seen broad benefits, while lab-grown supply chains may offer easier traceability on worker conditions.
How to tell lab diamonds from real diamonds
Lab-grown and natural diamonds are visually identical. Only specialised testing can determine origin reliably.
Always request the grading report. The GIA issues reports for lab-grown diamonds for transparency.
Do I still have to look out for the 4Cs?
Yes. Lab-grown diamonds also have inclusions and colour variations. Assess carat, colour, clarity and cut—they drive beauty and price regardless of origin.
Final word
Lab-grown can be a great way to achieve larger looks at lower prices—excellent for fashion and statement pieces.
If rarity and long-term value matter most, natural diamonds remain the traditional choice—each a unique piece of deep time that laboratories can’t truly replicate.