What are Lab Grown Diamonds?
A mined diamond is formed inside the earth's crust. It takes over a billion years, immense pressure and high temperature for the diamond to form. With application of advanced science and technology, it has become possible to highly accelerate this process and recreate the same geological circumstances in a laboratory above the earth. This has given birth to Lab Grown Diamonds.
How are Lab Grown Diamonds made?
There are two methods to grow diamonds in a laboratory -
Chemical Vapour Desposition (CVD) is a process used to create gem quality diamonds, optics and semi conductors. A diamond substrate is placed inside a chamber, this chamber is then infused with carbon rich gases (like methane) and heated. The gas is heated until the carbon atoms are seperated from the gas. These carbon atoms then fall onto the substrate (this process is called carbon rain) & build up layers over layers resulting in growth of rough lab grown diamond. The entire process takes between 5-10 weeks to grow gem grade Type ⅡA diamonds.
Modified versions of CVD are being used nowadays. The process differs in ways with which chemical reactions are initiated. Following are the modified CVD methods.
- Plasma enhanced CVD (PE CVD)
- Low pressure CVD (LP CVD)
- Microwave Plasma CVD (MP CVD)
- Ultrahigh Vaccum CVD (UHV CVD)
High Pressure High Temperature (HPHT) is a method which replicates the environment found beneath the earth's crust. In this process, "Growth cell" is placed in the HPHT chamber. This growth cell consists of the seed, refined graphite and a catalyst mixture of metals and powders. Consistent temperature of 1200-1300 degree celsius and more than 50,000 atmospheres of pressure is applied in the chamber. This leads the catalyst to melt which in turn causes the graphite to dissolve. This mixture is then allowed to cool which takes several days & allows carbon atoms to build upon the seed. The entire process has to be incredibly controlled to produce gem quality diamonds. Fluctuations in the process might stop the growth or create heavy inclusions in the diamond.
Following are some of the tools that are used to create high pressure and temperature in the chambers
- Belt Press - It is the founding technology for growing diamonds. Two anvils are used to create pressure. It is generally used to produce industrial diamonds and powders.
- Cubic Press - This is bulky in size and uses six anvils to create the necessary pressure. This is also used for industrial purposes.
- Bars Press - This one is most effective for gem quality diamonds. It uses inner and outer anvils to apply hydraulic pressure to the growth cell.
Brief Overview of the Manufacturing Process
Growers need to make sure they have the best seeds in order to grow good quality rough diamonds. The seeds act as the raw material for growing rough diamonds.
Diamond Growing Reactors
Selected seeds are now placed on a metal plate and put in the diamond reactor for processing. It is upto the grower's discretion whether to use CVD method or HPHT method to grow rough diamonds.
The seeds after going through the reaction in the machine, grow into rough diamonds over a period of time and are ready to be sent to factories.
Cutting & Polishing
Rough Lab grown diamonds are now cut and polished in the factories to yield polished diamonds.
The grown diamond is now ready to be set in jewelry.
How are Lab Grown Diamonds different from Earth Mined Diamonds ?
Since the lab grown diamonds go through the same conditions like the mined diamonds, they are totally comparable to earth mined diamonds. Lab grown diamonds display exactly the same Physical, Chemical & Optical characteristics like Earth Mined Diamonds. The only difference is that the Lab grown diamonds are engineered in a laboratory above the earth.
Mined VS Grown
|Chemical Composition||Crystalline Structure||Refractive Index||Dispersion||Hardness||Density|
How long have Lab Grown Diamonds been around?
The first commercially successful Lab grown diamond was created by Tracy Hall at General Electric in Dec 1954. This led to the rise of man-made industrial quality diamonds that were mainly dominated by GE Superabrasives & De Beers Industrial Diamonds. Since then Man made diamonds are used in wide array of industries such as Medical, Water treatment, Optics, Power transmission, Semi conductors etc. Only in recent years gem quality diamonds have been invented that could be used in making jewelry.
What are the benefits of opting for a Lab grown Diamond ?
Eco friendly-Lab made diamonds are created in a controlled environment in a laboratory above the earth. No eco systems are disturbed as there is no mining. On the other hand,mined diamonds have almost 7 times the impact on the eco sytem than lab made diamonds since, it causes land digging, soil erosion, relocation of people around a diamond rich mine, usage of oil & fuel, etc. Let us look at the chart below to compare eco sustainability of mined diamonds & lab made diamonds.
0.00091 hectares / carat
0.00000071 hectares / carat
Lost time Injury Rate
480 Litres (0.48 m3)/carat
70 litres (0.07 m3)/carat
8 days/100 employees per year
0 days/100 employees per year
Conflict free & Ethical-Since these diamonds are made in a laboratory they are guaranteed conflict free and ethical. With lab made diamonds one can be sure that the money has not been used to fuel rebels & wars. With mined diamonds one cannot guarantee it.
Value for money-One of the biggest advantage of lab made diamonds is that it makes luxury affordable for all. She either goes home with a bigger diamond or saving quite a few thousand dollars.
What are the different terms that are used to describe lab grown diamonds ?
- Above Earth diamonds
- Cultured diamonds
- Lab created diamonds
- Man made diamonds
- Lab made diamonds
As per the guidelines of FTC it is incorrect to call Lab grown diamonds Synthetic/Fake/Simulant.
How does one identify if a diamond is a Lab grown diamond?
Lab grown diamonds have same Physical, Chemical & Optical characteristics as mined diamonds. It is impossible even for a seasoned diamond dealer or a jeweler to say with the naked eye if a diamond is lab made or mined. Only with the help of advanced machinary, one can determine the origin of a diamond. Gemological laboratories can do the job as well.