How Lab Grown Diamonds Are Made?

The future of diamonds is no longer buried deep underground. It’s now being created in high-tech labs and sparkling brighter than ever! No pickaxes, no explosions - just pure science turning carbon into flawless brilliance.

Yes, we are boasting about lab-grown diamonds here ( why shouldn’t we? They deserve it!)

Are Lab-Grown Diamonds Like Natural Diamonds?

Short answer: Absolutely. 

Same atomic structure. Same fire and brilliance. Same “I-can’t-stop-staring-at-it” effect. 

The only difference? They don’t come with the baggage of traditional mining. No environmental destruction, no ethical dilemmas—just guilt-free luxury.

Lab-grown diamonds are created using two advanced techniques: HPHT (High-Pressure High-Temperature) and CVD (Chemical Vapor Deposition). These methods replicate the natural diamond formation process—just in a controlled environment

Curious about how the lab-grown diamond process works? Let’s explore the fascinating science behind their formation.

Related Article: Lab-Grown Diamonds vs Natural Diamonds

Methods of Creating Lab-Grown Diamonds 

Diamonds are the hardest naturally occurring material on Earth, formed under immense pressure and heat over 1–3 billion years (this can make a volcano jealous, seriously). But today, with the advancement of technology (thanks to modern science and a bit of human impatience),  this geological timeline is compressed into weeks.

Lab-grown diamonds are created through two primary techniques:

1. High-pressure high-temperature (HPHT) – A process that mimics Earth's deep mantle conditions.

2. Chemical Vapor Deposition (CVD) – A method that grows diamonds atom by atom (think sci-fi-esque method) using plasma-enhanced gas reactions.

Both methods produce genuine diamonds, but they take very different routes to get there. Let’s break them down:

High-Pressure High-Temperature (HPHT): The Old-School Powerhouse

This is the OG of lab diamond creation – pioneered in the 1950s when General Electric decided nature was taking too long. The HPHT diamond process recreates the brutal heat (1,500–2,000°C) and pressure (5–6 GPa) found 150 km underground, forcing carbon into submission until it becomes a diamond.

How Lab-Grown Diamonds Are Made In HPHT Process?

Step 1: Diamond Seed Placement – A tiny diamond seed is placed in a chamber filled with carbon (graphite) and a metal catalyst (iron, nickel, or cobalt).

Step 2: Crank Up the Heat – The chamber gets hit with insane amounts of pressure and heat, melting the carbon into a liquid state.

Step 3: Crystal Formation – As the temperature cools, the carbon atoms realign into a stunning diamond lattice.

Step 4: Finishing Touches – Some HPHT diamonds undergo further treatment to enhance clarity or tweak their colour.

HPHT Press Types:

• Belt Press – The grandparent of all presses—mainly used for industrial-grade diamonds.

• Cubic Press – Mass-produces diamonds efficiently (because why grow one when you can grow a bunch?).

• BARS Press – A sophisticated Russian innovation that produces large, high-quality single-crystal diamonds. Because, of course, Russia has a press for that.

HPHT Diamond Traits

• Contains tiny metallic inclusions (blame the catalysts).

• Naturally come in fancy colours—yellow (from nitrogen) and blue (from boron).

• They have higher thermal conductivity than CVD diamonds, which makes them a favourite for industrial cutting tools and semiconductors.

• Has a distinctive cuboctahedral growth pattern, which is basically diamond DNA for gemologists (visible under advanced spectroscopy).

Chemical Vapor Deposition (CVD): The Sci-Fi Diamond Lab

CVD lab-grown diamonds are where chemistry meets wizardry. Instead of crushing carbon under absurd pressure, the CVD diamond process is a plasma-assisted growth technique that builds diamonds layer by layer using hydrocarbon gases. 

It produces Type IIa diamonds, the rarest and purest kind—only 1–2% of natural diamonds meet this standard.

How Lab-Grown Diamonds Are Made In CVD Process?

Step 1: Seed Placement – Thin slices of HPHT-grown diamonds (usually Type Ib) are placed inside a vacuum chamber.

Step 2:Gas Infusion – The chamber is filled with hydrocarbon gases (mostly methane and hydrogen) and heated to a cozy 800–1,200°C.

Step 3: Atomic Magic – Microwaves, lasers, or hot filaments break down methane, freeing carbon atoms to settle onto the diamond seed—one layer at a time.

Step 4: Patience, Please – Growth is slow, around 0.1–1 mm per day, meaning large diamonds take weeks to form.

CVD Plasma Systems

• Microwave Plasma-Enhanced CVD (MPCVD) – The gold standard, producing ultra-pure diamonds with surgical precision.

• Hot Filament CVD (HFCVD) – Uses heated tungsten filaments but tends to introduce contaminants. Not ideal.

• Direct Current (DC) Arc Plasma CVD – Creates extremely high-energy plasma but isn’t widely used.

CVD Diamond Traits

• Ultra-high purity (Type IIa = no nitrogen = absolute clarity).

• Superior optical transparency—ideal for high-tech applications like quantum computing (yes, diamonds are in computers now).

• Starts brownish but can be treated to reach flawless white.

• Forms in layers, creating unique striations visible under UV fluorescence and infrared spectroscopy.

• By now, we believe that you have a pretty good idea of how lab-grown diamonds are made – now we are going to understand the key differences between these two amazing processes.

Related Article: How to identify a real diamond

HPHT vs. CVD: Key Differences 

The battle between HPHT (High-Pressure, High-Temperature) and CVD (Chemical Vapor Deposition) is where things get interesting. 

To get a deeper understanding of the differences between these two processes, this table will help (fingers crossed!)