1 thought on “Brown diamond”

  1. Brown diamonds have been produced since ancient times, but they are not loved by people. In the past, most brown diamonds were used for industrial use. In the 1980s, Agael in Australia produced brown diamonds. Australia strongly sell brown diamonds to the world, use various methods to promote, and vigorously improve its acceptance. Now brown diamonds are named after French wine, with light brown diamonds as champagne diamonds, and crown with dark brown diamonds as Cognic (Cognac) diamond. Under the champagne diamond jewelry design competition and attractive color level promotion, brown diamonds have now become popular fashion, mainly used for medium -priced diamond jewelry. Figure 3-13 is a natural brown diamond concentrated by the Arctic Light Diamond.
    The color of brown diamonds is mainly produced by the plastic deformation of the crystal. The higher the degree of plastic deformation, the deeper its brown. Observation in microscope F, the plastic deformation of the crystal is distributed in a brown band. The plastic deformation described here actually includes the real plastic deformation and non -recovered permanent deformation. Plastic deformation will return to the inherent cubic lattice structure under high temperature and high pressure, and the brown produced by plastic deformation will also disappear; permanent deformation will not be restored to the inherent cubic lattice structure through high temperature and high pressure treatment. The brown produced will not disappear.
    Figure 3-13 A Tino Hammid/Courtesy of Aurora Gem concentrated in the concentration of Arctic light and color diamonds
    No. 236, weighing 1.64ct
    The central part of the center produces a wide suction peak at 550nm. This absorption peak makes the diamond the color of purple -red tone. This wide absorption peak is relatively low, and it is always accompanied by a strong and un selective absorption, making the color brown, not high -saturated purple -red.
    The color of brown diamond is caused by the plastic deformation of the diamond crystal. As long as the stress inside the diamond crystal is eliminated, the plastic deformation of the lattice can be eliminated to improve the color of the brown diamond. Many IIA -type brown diamonds only have plastic deformation and do not have any other colors and capacity related to nitrogen. After high temperature and high pressure treatment of this ⅡA ​​brown diamond, it can eliminate plastic deformation, make the color of brown diamonds change, and even become completely colorless diamonds. The color can reach the highest level. Now the United States GM and several other companies in the world are engaged in the high temperature and high -voltage color change business of brown diamonds. The international diamond jewelry market is easy to buy colorless diamonds treated with high temperature and high pressure.
    The colorless diamond -free diamonds and natural colorless diamonds by high temperature and high pressure are almost the same. It is difficult to identify with the naked eye or gemstone instruments. However, the type of colorless diamonds treated with high temperature and high pressure is IIA, so it can be identified by measuring infrared spectrum measurement or ultraviolet spectrum measurement. The infrared spectrum of colorless diamonds treated with high temperature and high pressure does not have the infrared absorption peak of natural colorless ⅠA and IB diamonds. In addition, the ultraviolet deadline wavelength of type ⅠB colorless diamond -free diamonds is 220nm, while the ultraviolet deadline wavelength of natural ⅠA and type Ⅰb colorless diamonds is 330nm. Therefore, the UV cutter wavelength of the diamonds using UV lighting instruments is also used. It can accurately identify colorless diamonds with high temperature and high pressure treatment.
    If according to the law, colorless diamonds treated with high temperature and high pressure must explain to customers when selling. Do not conceal the facts of high -temperature and high pressure treatment. The U.S. GM uses lasers on the waist circumference of colorless diamonds treated with high temperature and high pressure treatment with high -temperature and high -pressure treatment "GE POL". Among them, "GE" is abbreviation of General Electric, "POL" is "POL" as a "POL" is the "POL" as a "POL" is the "POL". The abbreviation of PEGASUS Overseas LTD, Patto Gashos Overseas Corporation is a partner company selling high -temperature and high -pressure diamonds for General Electrical Appliances in the United States. GE POL laser labels can be identified when diamond trading. Although the color of high -temperature and high pressure treatment diamonds is permanent, the marking of high temperature and high pressure treatment is illegal.
    The largest champagne diamond is "Golden Giant", weighing 407.43ct; the largest Cowinek diamond is 111.59ct "Earth Star".

Leave a Comment