What are Lab-grown diamonds? Lab-grown diamonds have been around since the 1950’s. They were not gem quality and were used for industrial purposes. Only in the last decade have scientists been able to grow gem quality diamonds. They are created using advanced technology.. This is to precisely imitate the conditions under which mined diamonds are formed in the earth’s mantle. Their chemical structure is characteristic of the diamond crystal structure which is made up of carbon atoms. The result is a lab-grown diamond that exhibits the same physical, chemical and optical properties as a mined diamond, since they are composed of the same element, under essentially the same conditions.
Are they considered real diamonds? Yes, Lab-grown diamonds are real diamonds, sharing the exact same chemical composition, molecular structure, and physical and optical properties - something that cannot be said for any form of diamond simulant or imitation. Diamonds are solid forms of pure carbon. According to the FTC (Federal Trade Commission) CVD Lab Grown diamonds are “Diamonds”. Your standard diamond tester used in store will test CVD lab grown diamonds as “Diamonds” not “moisanite, simulant or CZ”.
How are lab-grown diamonds made vs mined diamonds? Mined diamonds were brought to the earth’s crust from its core where they were formed by volcanic eruption. It is believed by scientists that diamonds were formed 145km below the surface of the Earth, by the effects of extreme heat and pressure on carbon dioxide.The processes used to grow lab diamonds are much more efficient. There are two processes under which lab-grown diamonds are created, Chemical Vapour Deposition (CVD) and High Pressure-High Temperature (HPHT).
HPHT A small diamond seed is placed into a piece of carbon when the HPHT method is used. Using either a cubic press, a belt press or a split-sphere (BARS) press, the carbon is pressurised to approximately 103 500 bar. Simultaneously, the carbon is also exposed to temperatures over 1480 Celsius. This pressure and heat melts the carbon, resulting in the formation of a diamond around the initial diamond seed. The newly formed diamond then undergoes careful cooling.
CVD CVD uses a diamond seed (from a mined diamond). In this process a sealed chamber is filled with carbon-rich gases (typically methane and hydrogen) and is heated to over 760 Celsius with the diamond seed placed inside. With the use of technology similar to microwaves or lasers, these gases are ionized into plasma; in which the molecular bond of the gas is essentially broken down. A new diamond forms as the molecular bond in the gas is broken down and the pure carbon begins to bond to the diamond seed.
Can you tell the difference between lab-grown and mined diamonds? CVD TypeIIA diamonds are optically and chemically identical. It is impossible to tell the difference between a CVD lab grown vs mined diamonds even by the trained eye. Traditional methods of identification such as a diamond-tester or observation cannot distinguish between the two. This requires extremely sophisticated equipment that is specifically designed for the identification of lab grown diamonds used by a qualified and experienced gemmologist. In some instances HPHT diamonds are easier to distinguish as they may contain metallic inclusions, and will not always test perfectly with your in-store diamond tester. The minor differences observed by a gemologist with the use of this specialized equipment are found in nuances of crystal growth and trace elements.