What are Simulated Diamonds?

A long time ago, while in school I learnt that Diamonds are the hardest substances known to man. This probably explains why diamonds cost so much. These diamonds are formed in nature. It is a geological process.

So what are simulated diamonds?

Simulated diamonds are a creation of man; they are formed via a technological process. That is why they are also known as ‘manufactured’, ‘lab-grown’ or ‘cultured’ diamonds.

History of Simulated Diamonds

In 1797 it was first discovered that diamonds are comprised of pure carbon. Ever since then, attempts have been made by several people to produce diamonds synthetically.

Many scientists tried to make simulated diamonds using a variety of processes. Chief among them were Ferdinand Frederic Henri Moissan and Sir William Crookes. But no one met with much success.

The idea of making synthetic diamonds was also explored by the famous writer H.G. Wells in his short story titled ‘The Diamond Maker’ which was published in 1911.

In 1941 an agreement was made between General Electric, Norton and Carborundum to develop the process of artificial carbon synthesis. But the project was halted due to the Second World War. However, it resumed in 1951 after the war was over.

Eventually, in 1954 Howard Tracy Hall grew a synthetic diamond in a reproducible and verifiable process while he was working with General Electric. He even received a medal from the American Chemical Society for his work in 1972.

These experiments were also carried out in other countries and they too reported some amounts of success in their experiments. Chief among them were scientists in Sweden who were part of the QUINTUS project of ASEA, and Iljin Diamond in Korea. The people in Korea, it was later discovered, had stolen the technology from GE via an ex-employee.

Simulated Diamonds: Technology

There are two major methods which are used to create simulated diamond crystals.

The first and most popular method, which was devised by GE, is known as the High Pressure High Temperature (HPHT) method. There too, there are two different press designs which are used to grow the diamond crystals. The first is the method used by Howard Tracy Hall, which is called the belt press method. In the belt press method, two anvils, one from up and one from down, supply the pressure and heat currents to a cylindrical volume. The second method is known as the cubic press method. In this method, there are six anvils which provide pressure to a cube shaped volume.

The second method, devised by the Japanese, is known as Chemical Vapor Deposition (CVD) method. In this method the necessary environment is created for carbon atoms in a gas to settle on a surface for the diamond crystals to grow.

Simulated Diamonds: Properties

Simulated or synthetic diamonds have certain peculiar properties as compared with the typical properties of a natural diamond. They are:

The simulated diamonds may either be made up of a single continuous crystal, or they can be made up of several smaller crystals. The single crystal diamonds are used to make gemstones, while the smaller crystals are used in industrial applications.

The hardness of the diamonds made using the Chemical Vapor Deposition (CVD) method can be controlled depending upon their purpose. Diamonds have also been made which have been harder than natural diamonds.

No natural crystal is pure, because it can contain many different impurities. They usually give color to the crystals, and even add certain properties (depending upon the properties of the chemical which causes the impurity). Due to the processes used in the creation of artificial diamonds, there are chemicals which have to be used in the process. For example, nitrogen gives the diamond a yellowish color, while boron gives a bluish tinge.

Simulated Diamonds: Uses and Applications

Simulated or synthetic diamonds have many varied applications and uses. Due to their hardness diamonds have always been needed in machining tools. Due to cost and hardness factors, simulated diamonds are used on a wide scale in the various cutting tools.

Synthetic diamonds have also found their uses in the electronics industry. Conductive diamonds are used as electrodes in several cases.

Since diamonds are almost totally chemically inert, they are also used in the waste water treatment of organic effluents.

And of course, not to forget, synthetic diamonds are also used to make gemstones.

Thus, simulated diamonds are soon becoming the norm for various types of industrial and technological applications in the world.