What is a synthetic diamond?
Synthetic diamond is a kind of polycrystalline diamond which is crystallized and polymerized from diamond with a diameter of 10 to 30 nm. Early synthetic diamonds showed a light sugar color because nitrogen atoms in the air entered the diamond crystal. Through the improved production method of scientists, the artificial diamonds now produced are no different from natural diamonds in appearance. Due to the different production environment, the molecular structure of synthetic diamond is not a complete octahedral structure of natural diamond, but a complex structure, which will produce phosphorescence. With the maturity of artificial diamond production technology, its cost is low, and diamonds of various colors can be made, making a splash in the jewelry market.
What is the method of making synthetic diamonds?
A small natural diamond is placed in the center under the high temperature and high pressure environment of 2300℃ and15 ~180,000 atmospheres. The seed diamond is surrounded by high temperature molten metal, and the upper layer of the molten metal is graphite. In this environment, the carbon atoms in graphite will be arranged from metal atoms to diamonds, forming new diamonds. After the end of the Cold War, the Russian research team stopped the research on synthetic diamonds because of financial problems, and then resumed it with the capital injection of American jewelers. In 2005, the production capacity of American synthetic diamond production line reached 5 carats per hour. Recently, Russian scientists have developed an artificial diamond with a diameter of about 3 mm, which is completely consistent with the crystal structure of natural diamonds. It is believed that with the deepening of research, artificial diamonds similar to natural diamonds can be made in the near future.
What is the synthetic method of synthetic diamonds?
1. high temperature and high pressure synthesis method: temperature and pressure are still two key factors in making crystals. According to professionals who are engaged in diamond jewelry, the method is to make diamonds in ceramic containers, not underground. High pressure is provided by water pressure, and high temperature is generated by electricity, so that carbon surrounds the seed crystal with a diameter of 1mm and forms crystals.
2. Chemical vapor deposition synthesis method: after natural gas and nitrogen are heated, carbon plasma is formed in a pressure chamber the size of a dishwasher. Plasma is continuously deposited on the carbon bottom layer at the bottom of the pressure chamber, and gradually accumulates and hardens to form diamond slices, which are then cut into gem shapes.
When was the first synthetic diamond successful?
1954, synthetic diamonds were successfully synthesized for the first time. At that time, a group of researchers from General Electric Company made a diamond in the laboratory. They imitated the environment in which diamonds were formed in nature and subjected carbon to extremely high temperature and pressure. Also in the 1950s, another method of making synthetic diamonds was successfully developed. This method is called chemical vapor deposition (CVD), which deposits carbon in carbon-containing mixed gas into diamond matrix at very low pressure and relatively low temperature.