Synthetic Diamond

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Lab-grown diamond (LGD; also called laboratory-grown, laboratory-created, man-made, artisan-created, artificial, synthetic, or cultured diamond) is diamond that is produced in a controlled technological process (in contrast to naturally formed diamond, which is created through geological processes and obtained by mining). Unlike diamond simulants (imitations of diamond made of superficially-similar non-diamond materials), synthetic diamonds are composed of the same material as naturally formed diamonds – pure carbon crystallized in an isotropic 3D form – and share identical chemical and physical properties.

Laboratory-Grown Diamond Timeline:

1. 1950s: Union Carbide produces the first Chemical Vapor Deposition (CVD) diamonds in 1952. Others produce diamonds using the high pressure, high temperature (HPHT) method soon after. These diamonds are used for industrial purposes, such as in telecommunications and laser optics and as abrasives and more.

2. 1970s: General Electric researchers create the first gem-quality laboratory-grown diamonds. They are of high enough clarity and large enough size to be used in jewelry. GIA scientists publish the first scientific study of laboratory-grown diamonds in 1971.

3. Mid-1980s: Manufacturers grow commercial quantities of gem-quality laboratory-grown diamond crystals. These lab-created diamonds are initially mostly small and yellowish or brownish in color, but their quality improves over the ensuing decades.

4. 2000s: Gem-quality diamonds are created using the chemical-vapor deposition (CVD) method, which requires lower pressures and temperatures than the HPHT method.

5. Mid-2010s: Colorless laboratory-grown diamonds are available in the jewelry market in commercial quantities. Both HPHT and CVD continue to be popular methods of laboratory-grown diamond production.

HPHT and CVD (high-pressure high-temperature and chemical vapor deposition, respectively ) are the important methods used to produce synthetic diamond. The two processes still dominate synthetic diamond production. A third method in which nanometer-sized diamond grains are created in a detonation of carbon-containing explosives, known as detonation synthesis, entered the market in the late 1990s. A fourth method, treating graphite with high-power ultrasound, has been demonstrated in the laboratory, but currently has no commercial application.

The properties of man-made diamond depend on the manufacturing process. Some synthetic diamonds have properties such as hardness, thermal conductivity and electron mobility that are superior to those of most naturally formed diamonds. Synthetic diamond is widely used in abrasives, in cutting and polishing tools and in heat sinks. Electronic applications of synthetic diamond are being developed, including high-power switches at power stations, high-frequency field-effect transistors and light-emitting diodes. Synthetic diamond detectors of ultraviolet (UV) light or high-energy particles are used at high-energy research facilities and are available commercially. Due to its unique combination of thermal and chemical stability, low thermal expansion and high optical transparency in a wide spectral range, synthetic diamond is becoming the most popular material for optical windows in high-power CO2 lasers and gyrotrons. It is estimated that 98% of industrial-grade diamond demand is supplied with synthetic diamonds.

Both CVD and HPHT diamonds can be cut into gems and various colors can be produced: clear white, yellow, brown, blue, green and orange. The advent of synthetic gems on the market created major concerns in the diamond trading business, as a result of which special spectroscopic devices and techniques have been developed to distinguish synthetic and natural diamonds.

Natural diamonds are classified according to their optical properties, with most being Type I and having an absorption edge of around 330 nm, and a small group being Type II with an absorption edge of about 220 nm.

https://en.wikipedia.org/wiki/Synthetic_diamond

https://www.britannica.com/science/synthetic-diamond

https://4cs.gia.edu/en-us/laboratory-grown-diamond/

https://www.capetowndiamondmuseum.org/blog/2018/06/real-diamonds-vs-synthetic-diamonds/

https://cen.acs.org/articles/82/i5/FACETS-MAN-MADE-DIAMONDS.html

https://www.brilliantearth.com/lab-created-diamonds/

https://www.nature.com/articles/d42473-021-00066-x

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