Frequently asked questions about NOORDIA diamonds
Is lab-grown diamond a new thing?
Diamonds were first grown in the General Electric Co. lab in the 1950s, but they were not yet jewelry-grade stones that could be sold on the market. Only in the last few years have we been able to produce large, jewelry-quality diamonds that match or surpass natural diamonds in terms of desirability and beauty.
So laboratory-grown diamonds are not a new phenomenon, their industrial use is wide-ranging, and they have only recently become available for jewelry making.
How long does it take to produce a lab-grown diamond?
Depending on color and size, it takes 30-60 days to produce a diamond.
How are diamonds grown?
All lab-grown diamonds are grown by placing a diamond core in a heat and pressure chamber that reproduces the natural diamond formation process. Growing diamonds is extremely difficult, because you have to create the special conditions that lead to the formation of diamonds in the depths of the earth. A tiny slice of a Type IIA diamond is placed in a chamber where they can ensure long-lasting, stable, high temperature and pressure. As a result of crystallization, laboratory diamonds mature within six to ten weeks. They are then cut, polished and graded by the same world-renowned laboratories that also certify natural diamonds.
The two techniques most commonly used by laboratories are:
Chemical Vapor Deposition (CVD)
The diamond slice is then subjected to a process called chemical vapor deposition (CVD), where the crystals grow layer by layer in hot plasma. The result is a real rough diamond with all the natural properties of a mined diamond. The CVD process uses ultra-pure, carbon-rich gases in a controlled chamber. Carbon-based gases, such as methane, are heated until they disintegrate and the carbon atoms in them are separated. These tiny carbon atoms fall onto the diamond substrate and form layers, resulting in a rough diamond crystal. This process takes six to ten weeks and results in gem-quality Type IIa diamonds.
In recent years, CVD research has become increasingly popular, and modified versions of CVD are now being used. These processes differ in how they initiate the chemical reactions. Some of these are:
- Low Pressure CVD (LPCVD)
- Ultra High Vacuum CVD (UHVCVD)
- Plasma Assisted Chemical Vapor Deposition (PECVD)
- Microwave Plasma Vapor Deposition (MPCVD)
High Pressure High Temperature Process (HPHT)
The HPHT process mimics the natural diamond growth environment found deep within the Earth. The machines used are capable of creating pressures of nearly 60,000 atmospheres and temperatures of 2,500 degrees Celsius.
The growth cell contains all the elements needed to grow a diamond, including a core, refined graphite, and a catalyst mixture of metals and powders. The cell is placed in the center of the HPHT chamber. At a constant temperature and pressure of more than 50,000 atmospheres, the catalysts first respond to the added heat and pressure, changing from a solid state to a molten form.
The molten catalyst solution causes the graphite to dissolve in the cell. Once all the necessary conditions are met, the cooling process begins. This process takes several days and allows carbon atoms to build on the nucleus. The cell is removed from the HPHT machine after the growth cycle is complete. The new rough diamond is extracted and cleaned in preparation for final cutting and polishing.
The entire HPHT growth process requires a highly controlled environment to produce gem-quality diamonds. Any changes during growth can stop the diamond from growing or create inclusions that result in unusable diamonds. Every diamond must go through its entire growth cycle. Only after opening the HPHT chamber can we see the finished rough diamond, its color, clarity and size.
In the HPHT process, three main tools are used to provide the necessary pressure and temperature to produce laboratory diamonds:
- Bar press
- Belt press
- Cube press
What is a Type IIA diamond?
The world's most famous and most brilliant natural diamonds are all type IIA. Koh-I-Noor, Krupp, Regent and Southern Star all fall into this category.
Only the best 1-2% of mined diamonds can be called Type IIA. Of all diamonds, they are the purest and have the best thermal conductivity. As natural diamonds rise from the depths towards the earth's surface, they are usually deformed or imperfectly formed, picking up certain impurities.
Type IIA stones are almost completely free of these imperfections and deformations. All diamonds we sell are type IIA.
Does the diamond tester test positive for lab-grown diamonds?
Yes, these are real diamonds. Their composition is pure, crystalline elemental carbon. NOORDIA gems pass all the tests used to certify diamonds
What are the 4Cs?
4C is a concept known to many:
1. Colour, the color;
2. Clarity, purity;
3. Cut, grinding;
4. Carat, the carat weight.
But how important is it in pricing?
The diamond industry determines the price based on the Rapaport Diamond Report ® price list. The basis of the Rapaport list is the perfect brilliant polish. It can be observed that the price increases exponentially depending on the weight and purity. Apart from the weight, the color and inclusion class of the diamond is an important factor.
Why are mined diamonds more expensive than lab grown diamonds?
The mined diamond passes through the hands of at least 5 dealers from the mines to the customers, so this keeps its price constantly high.
On the other hand, laboratory-grown diamonds are ordered directly from the manufacturers. The short supply chain primarily explains the lower price, and of course the mining costs do not increase the price of the gems either.
