What is CVD diamond? The difference between CVD grown diamonds and natural diamonds

What is CVD diamond? The difference between CVD grown diamonds and natural diamonds

一 、What is CVD diamond?

CVD diamond is a polycrystalline diamond synthesized from diamond crystals with a diameter of 10 to 30 nanometers. Simply put, it is a laboratory-grown diamond.

二 、The difference between CVD grown diamonds and natural diamonds

1. CVD-grown diamonds can be understood as diamonds that are produced by artificially simulating the growth environment of diamonds and have the same composition as natural diamonds. That is, the authoritative laboratory diamond laboratory can identify and distinguish them. The production method is the difference between CVD-grown diamonds and natural diamonds.Natural diamonds are of course precious gemstones processed from diamonds. Stones are also valuable. Natural diamonds grow under a range of temperature and pressure conditions, which are higher than those used for CVD grown diamonds.At high temperatures, diamonds grow as octahedral crystals, but at lower laboratory temperatures they grow as crystals containing both octahedral and cubic crystal faces.

2. Structure: The difference between CVD-grown diamonds and natural diamonds is that one is naturally formed and the other is artificially processed, but the ingredients are the same, both are pure carbon structures, and the hardness is also the same. It is said that there are other artificial diamonds that are harder than natural diamonds. The Mohs hardness of natural diamonds is 10, making them the hardest material in nature.

3.Price: The price difference between natural diamonds and CVD-grown diamonds. Price is a reflection of value. Needless to say, the value of natural diamonds. People who don’t know about CVD-grown diamonds may think that they are very cheap. In fact, this is not the case. The production conditions of CVD-grown diamonds are harsh, so the cost of produced CVD-grown diamonds is also high. Even now, the conditions are relatively mature, and one carat of CVD-grown diamonds is Diamonds also cost several thousand yuan, while natural diamonds cost as little as 20,000 to 30,000 yuan per carat, and as much as 70,000 to 80,000 yuan per carat. It mainly depends on the quality of the diamond.

4. Quality: Because CVD-grown diamonds are artificially processed, their clarity and color will be better than ordinary diamonds. This is also the difference between CVD-grown diamonds and pure natural diamonds. Color and clarity have a great influence on the price of diamonds. The quality of natural diamonds cannot be generalized. There are good and bad diamonds. The quality of CVD-grown diamonds is often better, and the brilliance produced by CVD-grown diamonds is even better.

5. Size: CVD cultivated diamonds can produce more large diamonds, while large natural diamonds are rare and expensive

6.Processing: There are two main methods for processing CVD grown diamonds: high temperature and high pressure (HPHT drilling) and chemical vapor deposition (CVD drilling). The chemical vapor deposition method is suitable for producing large carat diamonds (mainly 1 carat).The chemical vapor deposition method uses microwave heating, discharge and other methods to activate carbon-based gases, such as methane, to dissociate carbon atoms and hydrogen atoms, and then combine the free carbon atoms to form diamonds. Usually CVD synthetic diamonds are carried out under low pressure and high temperature conditions. The pressure is generally less than one atmosphere and the temperature is about 1000 degrees.

 三、Can CVD diamonds be seen?

The first point that must be made clear is that the chemical composition of CVD diamonds is carbon, which is exactly the same as natural diamonds. However, CVD diamonds are synthetic diamonds through technical means, rather than naturally formed during geological changes.CVD diamonds are exactly the same as natural diamonds in terms of chemical composition, crystal structure, optical properties and physical properties. To use a very appropriate metaphor, the relationship between natural diamonds and CVD diamonds is more like that of human clones. CVD diamonds are truly diamonds. Therefore there is no problem of being seen.However, since the growth rate of CVD diamonds is much higher than that of natural diamonds, the fluorescence displayed by the spectrum under the illumination of high-tech equipment will be slightly different. However, this equipment is not a top diamond appraisal institution, and ordinary people do not have it. of this kind of equipment.