WHAT ARE LAB-GROWN DIAMONDS?
Lab-grown diamonds or cultured diamonds are grown using highly advanced technology and research, under strictly controlled laboratory conditions of high pressure and temperature, to precisely imitate the conditions under which mined diamonds were formed in the earth’s mantle. Their chemical structure is characteristic of the diamond crystal structure which is made up of actual 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 the same conditions.
ARE THEY REAL DIAMONDS?
Yes! Lab-grown diamonds are real diamonds.
The Federal Trade Commission (FTC) defines a diamond as pure crystallized carbon in the isometric cubic system; irrespective of whether it is grown in a lab or mined from the earth’s mantle. This definition of a diamond includes both lab and mined diamonds as they have the same properties chemically, physically and optically. Thus, regardless of where or how the diamond originated, a diamond is a gemstone composed of crystallized carbon.
WHAT DO LAB AND MINED DIAMONDS HAVE IN COMMON?
Chemical Composition: C (Carbon)
Crystalline Structure: Cubic
Hardness (MOHS): 10
Refractive Index: 2.42
HOW ARE LAB 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 (1482OC+) and pressure (511 131kg/cm2 or 50 125 bar) 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, namely Chemical Vapour Deposition (CVD) and High Pressure-High Temperature (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.
Like the HPHT process, CVD uses a small diamond seed (often an HPHT 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. after the diamond is grown, additional treatments can be used, such as irradiation or heat, to change or enhance the diamond’s colour.
Mined diamonds are said to have taken billions of years to form under the earth’s surface. Lab grown diamonds take between 5-10 days to grow 1 carat of fancy colour and 2+ weeks to grow white diamonds. If the process of growing diamonds is rushed, it will cause the crystal structure to fracture, thus it is important not to rush the process.
CAN YOU TELL THE DIFFERENCE BETWEEN LAB-GROWN AND MINED DIAMONDS?
A mentioned before, the two types of diamond are identical optically and chemically. It is impossible to tell the difference between lab grown and mined, 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 gemologist. The minor differences observed by a gemologist, with the use of this specialized equipment, are found in nuances of crystal growth and trace elements.
CERTIFICATION AND GRADING
Lab diamonds come with a grading report, just like mined diamonds. The most common being from the International Gemological Institute (IGI).
WHAT ARE THE BENEFITS OF A LAB-GROWN DIAMONDS?
- They are equally as beautiful as mined diamonds
- They are socially responsible: peace of mind that they are not in anyway linked to the blood diamond trade (however, our natural diamonds are also ethically sourced)
- They have smaller environmental impact
- They are less expensive
- You can get better quality (colour, clarity, cut) for the price
IS A LAB-GROWN DIAMOND FOR ME?
The decision is a personal one. One should draw a conclusion for oneself based on the above information. It all boils down to what is important to you, what look you want to achieve and what your budget allows for the end goal.