Lab diamond is artificially synthesized in the laboratory and has basically the same physical properties, chemical composition and crystal structure as natural diamond.At present, the methods for lab diamond include high temperature and high pressure synthesis (HPHT synthesis) and chemical vapor deposition (CVD).
Basic characteristics of high-temperature and high-pressure lab diamond
HTHP lab diamond are often cubes, octahedra and their polymorphs; their colors are usually yellow and tan, with ribbons, metal inclusions and other features inside. Unfused metal inclusions are needle-like, flake-like, and pillar-like Or irregular appearance, with metallic luster, making lab diamonds magnetic.Lab diamonds usually have no fluorescence under long-wave ultraviolet rays, and often have yellow, green-yellow, and orange-yellow fluorescence under short-wave rays. Lab diamonds have characteristic banding phenomena under ultra-short-wave ultraviolet or cathode rays. Different growth regions show different colors of fluorescence, band. At present, diamonds synthesized at high temperature and pressure are mainly used in industry.
Basic characteristics of CVD lab diamond
CVD lab diamond single crystals are mostly plate-shaped, and occasionally small octahedral and rhombic dodecahedral surfaces can be seen at the edges. Early CVD lab diamonds were mostly dark brown or light brown, while recently discovered CVD lab diamonds were proved to have undergone post-high temperature heat treatment, so the color was colorless or nearly colorless.CVD lab diamonds have fewer internal inclusions, and individual needle-shaped, black irregular inclusions can be seen。However, this cannot be used as a basis for distinguishing natural diamonds ,HTHP lab diamonds from CVD lab diamond.Metal inclusions do not appear in CVD lab diamonds, so they are not magnetic. The CVD method can produce high-quality gem-quality large diamonds, so it is mostly used in the field of jewelry.
The relationship between natural and synthetic diamonds
Natural diamonds are rare and precious, so their market value is relatively high. However, the physical properties of lab diamonds are the same as natural diamonds. Natural diamonds cannot be distinguished from lab diamonds with the naked eye, and can only be detected with the help of professional identification equipment.
In general terms, lab diamonds is a diamond that grows slowly using natural diamonds as a matrix to simulate the natural diamond production environment in the laboratory. It is a real diamond and it made of pure carbon and has a hardness of Morse 10. Its chemical composition and physical properties are exactly the same as natural diamonds.