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How are Lab Grown Diamonds Made?

If you're in the market for a new diamond, you may have already heard about lab-grown diamonds. With increasing awareness of the environmental and ethical concerns surrounding the diamond industry, lab-grown diamonds have emerged as a popular alternative to mined diamonds over the past two decades or so. In this article, we're going to delve into everything you need to know about the creation of lab-grown diamonds, focusing on the two primary methods for their creation: High-Pressure High Temperature (HPHT) and Chemical Vapour Deposition (CVD).

Lab Grown Diamonds: Know the Basics

Lab-grown diamonds are actually identical to natural diamonds in every way but are created in a controlled environment using cutting-edge technology, rather than being extracted from the depths of the Earth.

Shoppers are increasingly choosing lab-grown diamonds over mined diamonds for so many reasons: they're more sustainable, more affordable, and provide complete assurance that they were ethically sourced.

Lab diamonds are real diamonds that are optically, physically, and chemically identical to their mined counterparts and will test as just like a mined diamond when a diamond tester is used.

High-Pressure High Temperature (HPHT) Diamonds: The Original Method

The HPHT method is the original method of creating lab-grown diamonds.

During HPHT, diamonds are made in a lab by replicating the high-pressure, high-temperature conditions that form diamonds underground in the Earth.

The HPHT process consists of three primary techniques:

1. Belt Press: In this method, a carbon source, typically graphite, is subjected to extreme pressures and temperatures using hydraulic presses, which compress the carbon between two anvils.

2. Cubic press: This technique involves placing a carbon source within a pressure cell, which is then compressed by six anvils, generating a uniform pressure and temperature throughout the sample.

3. Split-sphere (BARS) press: In this method, a carbon source is placed within a pressure cell surrounded by a cemented carbide sphere in this procedure, and the spherical is then squeezed between two anvils, creating the conditions necessary for diamond formation.

The HPHT diamond machine is a device used to simulate the natural conditions of the Earth's mantle by subjecting carbon to high pressure and temperature, resulting in the formation of diamonds.

Chemical Vapour Deposition (CVD) Diamonds: A More Recent Approach 

A more contemporary technology for producing lab-grown diamonds is chemical vapour deposition (CVD).

CVD diamonds are created by injecting a carbon-containing gas (often methane) into a vacuum chamber and exposing it to high-energy plasma.

Carbon atoms are liberated from the gas and deposited on a substrate, where they condense and create diamond layers.

CVD has surpassed HPHT in popularity for several reasons:

The ability to produce larger diamonds: When compared to HPHT, CVD enables the creation of larger diamonds which makes it a popular alternative for manufacturing larger stones.

Fewer inclusions: CVD diamonds often have fewer inclusions than HPHT diamonds resulting in superior overall quality.

Easier colour control: CVD diamonds can be more easily manipulated to produce a wider range of colours from near-colourless to vivid hues.

Comparing HPHT and CVD Diamonds: Similarities and Differences

The fact is that both HPHT and CVD methods can produce high-quality lab-grown diamonds that are nearly indistinguishable from natural diamonds.

With that said, the two methods do have similarities and differences:

The similarities:
1. Both methods create real diamonds: HPHT and CVD diamonds are both chemically, physically, and optically identical to natural diamonds.

2. Grading standards: Diamonds produced using either method can be graded using the same criteria as mined diamonds, including the 4Cs: carat, colour, clarity, and cut.  

The differences:
1. Inclusions: HPHT diamonds tend to have more metallic inclusions than CVD diamonds, which may affect their clarity and overall quality.

2. Colour: While both methods can produce a range of diamond colours, CVD diamonds are often easier to control in terms of colour, resulting in a wider variety of hues.

3. Growth time: HPHT diamonds typically grow faster than CVD diamonds but the latter method allows for the growth of larger stones.

4. Price: HPHT diamonds can be more affordable than CVD diamonds due to their faster growth rate, but CVD diamonds often have higher quality with fewer inclusions, which may increase their value.

Raw Diamonds: The HPHT process typically produces raw diamonds of a cuboctohedron shape, whereas the CVD process typically produces raw diamonds of a cuboid shape. 

Choosing Between HPHT and CVD Diamonds 

Ultimately, the choice between HPHT and CVD diamonds comes down to personal preference and budget.

They’re both great options. Both methods produce stunning lab-grown diamonds that are more sustainable and ethical than mined diamonds. And while HPHT diamonds may be more affordable and grow more quickly, CVD diamonds often boast fewer inclusions and a wider range of colours.

Regardless of the method used to create them, lab-grown diamonds are revolutionizing the diamond industry by offering a beautiful, sustainable, and ethically sourced alternative to mined diamonds.

Advancements in Technology and the Future of Lab-Grown Diamonds 

Lab-grown diamonds are likely to become more impressive and polished in their manufacturing as technology advances in the upcoming years. There’s no doubt about it.

And as a result of this development, lab-grown diamonds are expected to rise in quality, variety, and competitive pricing.

The development of novel HPHT and CVD processes also has the potential to yield diamonds with improved clarity, colour uniformity, and size. Not only that though, but developments in diamond-growing technology could open the door to using lab-grown diamonds in fields other than jewellery, such as electronics, optics, and other industrial uses. There's no doubt that technology will continue to improve, making lab-grown diamonds an even more appealing alternative for shoppers interested in acquiring diamonds that are beautiful, ethical, and sustainable.