Synthetic diamond

History of Synthetic Diamond Development

• Antoine Lavoisier discovered the similarity between a diamond's crystal lattice and carbon's crystal structure, leading to initial attempts to produce diamonds.
• James Ballantyne Hannay and Ferdinand Frédéric Henri Moissan successfully produced diamonds by heating charcoal with iron in a carbon crucible.
• Other scientists, including Sir William Crookes and Otto Ruff, also claimed success in producing synthetic diamonds.
• Dr. J. Willard Hershey replicated Moissan and Ruff's experiments, producing a synthetic diamond.
• ASEA, Sweden's major electrical equipment manufacturing company, achieved the first known diamond synthesis in 1953 through their project called QUINTUS.
• General Electric (GE) collaborated with Norton and Carborundum companies in 1941 to develop diamond synthesis.
• The GE team successfully synthesized diamonds using a hydraulic press and tungsten carbide anvils.

Properties and Applications of Synthetic Diamonds

• Synthetic diamonds have properties such as hardness, thermal conductivity, and electron mobility that can be superior to naturally formed diamonds.
• They are widely used in abrasives, cutting and polishing tools, and heat sinks.
• Synthetic diamond is being developed for electronic applications, including high-power switches, high-frequency transistors, and light-emitting diodes.
• Synthetic diamond detectors are used in high-energy research facilities and are available commercially.
• Synthetic diamond is popular for optical windows in high-power CO2 lasers and gyrotrons.

Distinction and Concerns

• Synthetic diamonds can be cut into various colors, including clear white, yellow, brown, blue, green, and orange.
• The presence of synthetic gems in the market raised concerns in the diamond trading business.
• Special spectroscopic devices and techniques have been developed to distinguish synthetic and natural diamonds.
• Synthetic diamond production is estimated to supply 98% of industrial-grade diamond demand.
• Synthetic diamonds with different nitrogen impurity content can result in different shades, such as yellow diamonds with higher nitrogen content and transparent diamonds from pure carbon.

Manufacturing Technologies for Synthetic Diamond

• Methods used include high pressure and high temperature (HPHT), chemical vapor deposition (CVD), explosive formation, and sonication.
• HPHT method uses belt press, cubic press, or split-sphere (BARS) press to supply pressure and temperature.
• Diamond seeds are placed at the bottom of the press and dissolved in molten metal to form synthetic diamond.
• CVD method involves carbon plasma depositing carbon atoms onto a substrate to form diamond.
• Other methods involve detonation nanodiamonds or sonication of graphite solutions.

Impact and Challenges of Synthetic Diamond

• Rise in undisclosed synthetic melee diamonds found in set jewelry and diamond parcels.
• Not all dealers make an effort to test diamond melee for natural or synthetic origin.
• International laboratories are making improvements in synthetic melee identification.
• Synthetic diamonds can be produced up to 25 carats for research purposes.
• Growth of most synthetic diamonds is terminated around 1-1.5 carats for economic reasons.

Synthetic diamond Data Sources