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This lesson is essential for modern gemology. The market has shifted dramatically, and a professional must be able to navigate the “Lab-Grown Revolution” with scientific facts, not just marketing hype.

Lab-Grown Diamonds: The Reality Check

The Identical Twin

If I place two diamonds in front of you—one mined from 200 kilometers below the Earth’s surface 1 billion years ago, and one grown in a laboratory in 6 weeks—could you tell the difference?

The Reality Check: With a 10x loupe and the naked eye, the answer is no. Even a master gemologist cannot distinguish a high-quality lab diamond from a natural one without specialized scientific equipment. They are chemically, physically, and optically identical. They are both pure carbon crystals.

1. How They Are Grown (The Two Methods)

As a professional, you must understand the two distinct “recipes” for a diamond:

HPHT (High Pressure High Temperature): This mimics the Earth. A tiny diamond “seed” is placed in carbon and subjected to massive pressure and intense heat. These often have a distinct “cube-octahedral” growth shape before being cut.
CVD (Chemical Vapor Deposition): This is like “3D printing” a diamond. A diamond seed is placed in a vacuum chamber filled with carbon-rich gas (like methane). A plasma beam breaks down the gas, and the carbon atoms rain down, layering onto the seed.

2. The “Inclusion” Secret: How Pros Tell the Difference

While the stones are “identical,” the way they grow leaves different “growth fingerprints.”

Metallic Inclusions (HPHT): Because HPHT uses a molten metal flux to dissolve carbon, tiny bits of metal can get trapped inside. If a diamond is attracted to a strong magnet, it’s almost certainly an HPHT lab stone.
Strain Patterns (CVD): CVD diamonds grow in layers. Under a specialized “polariscope” (a tool with polarized filters), natural diamonds show a “tatami” or cross-hatch strain pattern, while CVD stones show a different, linear “columnar” growth.

3. The Economic Reality: Value vs. Price

This is the most important part of your “Reality Check” for clients:

The Price: Lab-grown diamonds currently sell for 80% to 90% less than natural diamonds. You can buy a 2.00ct Lab diamond for the price of a 0.50ct Natural diamond.
The Value: Natural diamonds are a finite resource (rarity-based value). Lab diamonds are a manufactured technology (supply-based value).
The Reality: Just like TVs or iPhones, the technology to grow diamonds is getting cheaper. A lab diamond bought today will likely be worth significantly less in five years. A natural diamond’s value is historically more stable due to scarcity.

4. The “Sustainability” Myth

Many people buy Lab-grown because they believe it is “greener.”

The Truth: Growing a diamond requires a massive, constant amount of electricity (the machines run at temperatures hotter than the surface of the sun).
The Pro Insight: Whether a lab stone is “green” depends entirely on the energy source of the factory. A lab in a coal-powered region has a massive carbon footprint; a lab powered by solar is a different story.

The Quick Win: The “Inscription” Check

How do you quickly protect yourself as a trader?

Always look at the Girdle. Almost all reputable lab diamonds are laser-inscribed by labs like GIA or IGI with the words “LABORATORY GROWN” and a report number. If you see a high-quality 2-carat stone with no inscription and a suspiciously low price, your “alarm bells” should be ringing.

Summary for Students:

Lab diamonds are real diamonds (not cubic zirconia or moissanite).
They require advanced machinery (not just a loupe) to identify with 100% certainty.
They are a lifestyle purchase, while natural diamonds remain the investment purchase.