The Raw Materials

Man-made diamonds suitable for industrial use were first produced in a laboratory in the 1950s. While gem-quality diamonds were produced in a laboratory for the first time in 1971, it was not until the mid-2010s that colorless laboratory-grown diamonds entered the gem and jewelry market in commercial quantities.

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Today, laboratory-grown diamonds are created by two methods, according to Dr. James Shigley, GIA Distinguished Research Fellow, who has been researching laboratory-grown diamonds at GIA for more than 30 years.

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High pressure, high temperature (HPHT) diamonds are produced in a laboratory by mimicking the high pressure, high temperature conditions that form natural diamonds in the Earth. This process produces a distinctively shaped laboratory-grown diamond crystal.

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The chemical vapor deposition (CVD) method involves breaking down the molecules of a carbon-rich gas, such as methane, into carbon and hydrogen atoms, which then are deposited on diamond seeds to produce a square-shaped, tabular diamond crystal.

Growing diamonds by either method typically requires less than a month for most sizes. Most CVD-grown diamonds require additional treatments like heat or irradiation to enhance or change their colors after the growth process.

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Typically, laboratory-grown diamonds have weighed a carat or less, but as technology and techniques improve, larger stones have appeared in the market.