Common consumer misunderstandings about laboratory-grown diamonds
Lab-grown diamonds have the same crystal structure, chemical composition, optical properties, and physical properties as mined diamonds: the carbon atoms are arranged in a cubic crystal structure. And cultivated diamonds and mined diamonds of the same quality cannot be distinguished with the naked eye.
Natural diamonds are good and bad. Cultivated diamonds are the same, there are good and bad. The quality of cultivated diamonds produced by each factory varies greatly according to its own level of technology. The difference in color and clarity is relatively large. In other words, not all lab-grown diamonds are colorless and flawless, and the quality is also uneven. The grading standards for cultivated diamonds and natural diamonds (4C) adopt the same set of grading standards, and they are graded by a professional gemological appraisal laboratory.
Cubic zirconia and Moissanite are fake diamonds. Although many Moissanite sellers say they are diamonds when short videos such as Douyin are broadcast live, they are actually deceptive. Laboratory-grown diamonds have exactly the same fire, brightness, and diamond luster as natural diamonds, and will not fade or change color over time.
How do cultivated diamonds grow?
Manufacturing cultivated diamonds is one of the most precise and difficult manufacturing techniques in human history. After nearly 60 years of hard work, it has finally developed a clarity close to that of a gem-quality diamond. Up to now, there are two mainstream growth methods for cultivating diamonds: high pressure and high temperature (HPHT) and chemical vapor deposition (CVD).
HPHT diamond growth occurs in large presses. Put the small diamond seed into the diamond synthesis block and insert the graphite into the top of the diamond seed. The pressure is heated to 1500°C and pressurized to tens of thousands of times the atmospheric pressure. Under this extreme temperature and pressure, the graphite in the growth cell melts into liquid carbon, then slowly crystallizes onto the diamond seeds and slowly grows into diamond crystals. This process is long and completely closed. The clarity of cultivated diamonds produced under such high temperature and such high pressure is relatively uncontrollable, and only a few percent of it can achieve vvs clarity. very small.
CVD diamond growth is called vapor deposition and takes place in a vacuum plasma reactor. This method also requires a diamond flake as the substrate. When it is produced, the carbon atoms of the diamond fall on the seed sheet layer by layer like snowflakes. After several days and weeks of growth, the thin seed sheet grows from the thin seed sheet to thick. Of cultivated rough diamonds. Of course, this process also needs to constantly take out the blank for polishing and correction. Diamonds grown in this way are suitable for growing large-sized cultivated diamonds because each one requires considerable effort. If you use this method to grow small-sized cultivated diamonds, the cost is very high and it is not cost-effective. The clarity of cultivated diamonds grown by this method is relatively easy to control, but the color is not easy to control. At present, there are almost no factories in the world where this method can stably grow D-color cultivated diamonds.
Common misunderstandings about cultivated diamonds
Diamond-mining jewelers often promote many incorrect “facts” of cultivating diamonds to create consumers’ fear, uncertainty, and doubts about cultivating diamonds. The following are the most common misunderstandings.
Misunderstanding 1: Lab-grown diamonds are cheap to manufacture
This is the most common misunderstanding and is completely wrong. De Beers self-reported the cost of diamond mining in 2015 at US$104 per carat (for rough diamonds). The actual cost of cultivating each diamond in the laboratory is several times the cost of De Beers and other mining companies to dig diamonds from the earth, even if the fixed cost of the machinery required to cultivate diamonds in the laboratory is ignored, as well as cutting, The cost of polishing and grading diamonds is exactly the same as that of natural diamonds.
Misunderstanding 2: All lab-grown diamonds are colorless and flawless
The process of growing diamonds in the laboratory is very similar to that of mining diamonds. The same types of inclusions and defects found in mined diamonds may also appear in laboratory-grown diamonds. If the diamond crystals grow too fast, tiny cracks (feathers) may appear in the diamond. There may also be small inclusions of trace elements or other growth defects, causing the diamond to be close to colorless or slightly inclusions. Laboratory-grown diamonds are independently graded by professional independent gemological laboratories according to exactly the same standards as mined diamonds. These laboratories also classify the mined diamonds.
Misunderstanding 3: Lab-grown diamonds, like Moissanite and cubic zirconia, are fake diamonds
The diamonds made in the laboratory are genuine diamonds: carbon atoms are arranged in the cubic crystal structure of the diamond. The only difference between mining diamonds and laboratory cultivating diamonds is the source of the diamonds. Cultivated diamonds and mined diamonds have exactly the same physical properties. Moissanite and cubic zirconia are not diamonds. They are fake diamonds. In the past few years, some merchants often used this to pretend to cultivate diamonds. These are unscrupulous merchants. Today, in 2021, we still see some Moissan diamond manufacturers blatantly holding moissanite diamonds at the Shenzhen International Jewelry Fair. Sangzuan told customers that this is a cultivated diamond, which is very shameful. In fact, the chemical composition of Moissanite is silicon carbide, and the carbon content of cubic zirconia is zero. Diamonds, whether mined or cultivated, are made entirely of carbon. In other words, Moissanite and cubic zirconia are cheap fakes of diamonds of completely different materials. Cultivated diamonds are chemically and optically the same as natural diamonds.