Diamonds are successfully synthesized in the lab in the last century after countless failures for hundreds of years. Currently, there are two synthesis methods for gem diamonds, namely the High-Pressure, High-Temperature (HPHT) and the Chemical Vapor Deposition (CVD).
They are diamonds grown artificially in a laboratory that simulates the growth of natural diamonds under high temperature and high pressure in the earth's crust.
"Lab. Grown Diamonds":
They are crystallized through artificially synthetic method, including the High-Pressure, High-Temperature (HPHT) and the Chemical Vapor Deposition (CVD), being called “Lab. Grown Diamond” in the diamond identification.
Synthetic Diamond vs Natural Diamond:
Not only appearance and composition but also physical and chemical properties of synthetic diamond are as the same as those of natural ones. The difference lies in the way they grow: natural diamonds are mined from the earth but lab. grown diamonds are created in the stimulating growth of natural diamonds in the lab, which can’t be distinguished by eyes or traditional instruments. If without high resolution instruments, synthetic diamond can stand out for more “perfect clarity” and “reasonable price”.
Please refer to the following diamond classification chart:
In July 2018, the FTC’s decision resoundingly rejected the arguments of De Beers’ lobbyists, instead choosing to side with science on the definition of a diamond — A crystal of carbon, regardless of subterrestrial or superterrestrial origin.
Here’s the FTC’s new definition: A diamond is a mineral consisting essentially of pure carbon crystallized in the isometric system.
The FTC justified their change as follows:
The final Guides therefore eliminate the word “natural” from the diamond definition. When the Commission first used this definition in 1956, there was only one type of diamond product on the market — natural stones mined from earth. Since then, technological advances have made it possible to create diamonds in a laboratory. These stones have essentially the same optical, physical, and chemical properties as mined diamonds. Thus, they are diamonds.
The distinctions between these lab-created diamonds and mined stones are addressed elsewhere in the Guides. Since it is no longer correct to define diamonds as “natural,” the final Guides do not include “natural” in the diamond definition.
There is no such thing as synthetic gold.
There is no such thing as synthetic platinum.
There is no such thing as synthetic carbon.
There is no such thing as synthetic diamond.
In light of the new guidance from the Federal Trade Commission (FTC), the Diamond Producers Association may consider changing the slogan from "Real diamonds" to "Carbon crystals are diamonds, regardless of origin".
[Conclusion]:Lab-created diamonds have essentially the same optical, physical, and chemical properties as mined diamonds. Thus, they are diamonds.