What is CVD HPHT ?

​1. Natural Diamonds

          Formed millions of years ago deep beneath the Earth's crust, diamonds are created under extremely high temperatures and pressures. Carbon atoms crystallize into diamonds at depths of approximately 150-200 km below the Earth's surface, where the average temperature is 900-1,300°C and the pressure is 45-60 kilobars (about 50,000 times the atmospheric pressure at the Earth's surface).

           Under these conditions, diamonds crystallize into eight-sided, transparent forms with various colors, including colorless, and are considered the hardest gemstones. Diamonds are brought to the surface through volcanic eruptions of magma.

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2. Synthetic Diamonds / Imitation Diamonds (CZ, Moissanite)

          Synthetic diamonds, CZ diamonds (Cubic Zirconia), also known as Russian or Swiss diamonds, were originally created as a substitute for natural diamonds, intended for use in silver or fashion jewelry due to their lower cost. They are commonly used in jewelry priced in the hundreds to thousands of dollars because they visually resemble natural diamonds. However, CZ diamonds can be distinguished from natural diamonds by experts with the naked eye.
          Over time, developments have led to synthetic diamonds that more closely resemble natural ones, resulting in Moissanite (full name: Moissanite), which is made from the rare mineral Silicon Carbide, first discovered in a meteorite crater. Moissanite generally has more brilliance, better fire, and more appealing facets than CZ diamonds, though they are still relatively easy to distinguish.
In summary, synthetic diamonds or imitation diamonds can be identified with the naked eye.

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3. Lab-Grown Diamond (HPHT, CVD)

          Lab-Grown diamonds represent an advanced innovation. Lab-Grown diamonds are created through the crystallization of carbon atoms in a controlled laboratory environment, simulating the conditions under which natural diamonds form. Lab-Grown diamonds can be cultivated using two different methods:

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         3.1.  HPHT Diamond  (High-Pressure High Temperature)

HPHT diamonds are an early method of lab-grown diamond production, beginning in the 1950s. In addition to creating diamonds, the HPHT process can also be used to enhance the clarity and color of natural diamonds, achieving higher clarity or various colors such as pink, green, blue, or yellow.

The HPHT (High Pressure High Temperature) method for creating diamonds involves placing small diamond seeds into carbon, which is a key element in diamond cultivation. The diamond seeds are subjected to high heat and pressure, simulating the natural conditions under the Earth's surface where diamonds form. When exposed to temperatures up to 1,500°C and extremely high pressure, the carbon melts and crystallizes around the seeds, forming diamonds. As the diamond mass cools, it becomes pure carbon diamond in the form of a 14-sided shape (cuboctahedron).

 

          3.2.  CVD Diamonds (Chemical Vapor Deposition)

CVD diamonds were developed in the lab in the 1980s, representing a more recent evolution compared to HPHT. They are produced using lower pressure and smaller machinery, resulting in reduced production costs.

The process of creating CVD diamonds involves placing diamond seeds in a high-temperature, sealed chamber reaching up to 800°C. Carbon dioxide gas is introduced and ionized, causing pure carbon to deposit onto the seeds, gradually crystallizing into diamonds in a cubic form.