Another color change detection processing of the blue Topaz is emitting heat. According to U. Heen and H. Bank 1990 study, the natural blue Topaz PL peak heat two, which are located in 250 and 500 of temperature, luminous intensity and the former is larger than the latter. According to the site to deal with blue Topaz, whether by -rays, electron or neutron irradiation source for the thermal-luminescence peak at 400 after it, and showed single-peak form.
Better approach is the recent identification of Xin-Qiang Yuan et al 2006 found cathodoluminescence, natural blue Topaz irradiation treatment than many of strong cathodoluminescence.
In 2000 about Co2 ion diffusion processing Topaz appear in the market, the overall visual Topaz color was akoya pearls blue-green color, but blue-green color is limited to the surface thickness of lt5m, internal color, and surface non-uniform yellow to brown spots aggregation. Blue Topaz that is characterized by the identification of orange-red color filter was next, Topaz gathering spots uneven surface and color concentration area. Laser Raman spectroscopy by Co2 -O bending vibration derived 731,627,504 cm-1 three wide and 200cm-1 band of sharp peaks.
Brazil pink and red Topaz production in the region of the yellow and orange Topaz product by heat treatment.
Fifth, the quality evaluation of Topaz
Topaz color depends freshwater pearls largely on the quality, the net degree of processing, such as the quality and weight.
1. pearl jewelry Color
Topaz dark red the highest value, followed by pink, blue and yellow Then, the minimum value of colorless Topaz.
2. Clarity
Often Topaz gas - liquid inclusions and fissures, with inclusions and cracks will affect the value of persons.
3. Processing
Topaz quality of the glass should have a clear gloss, and attention should be paid when processing can not be engraved with pearl necklace its major surface parallel to the direction of cleavage, it would be difficult to carry out polishing, will affect the value of precious stones.
4. Weight
Although Topaz for the mid-precious stones, the weight of the larger more common, but, like other precious stones, the greater are the more precious.
Better approach is the recent identification of Xin-Qiang Yuan et al 2006 found cathodoluminescence, natural blue Topaz irradiation treatment than many of strong cathodoluminescence.
In 2000 about Co2 ion diffusion processing Topaz appear in the market, the overall visual Topaz color was akoya pearls blue-green color, but blue-green color is limited to the surface thickness of lt5m, internal color, and surface non-uniform yellow to brown spots aggregation. Blue Topaz that is characterized by the identification of orange-red color filter was next, Topaz gathering spots uneven surface and color concentration area. Laser Raman spectroscopy by Co2 -O bending vibration derived 731,627,504 cm-1 three wide and 200cm-1 band of sharp peaks.
Brazil pink and red Topaz production in the region of the yellow and orange Topaz product by heat treatment.
Fifth, the quality evaluation of Topaz
Topaz color depends freshwater pearls largely on the quality, the net degree of processing, such as the quality and weight.
1. pearl jewelry Color
Topaz dark red the highest value, followed by pink, blue and yellow Then, the minimum value of colorless Topaz.
2. Clarity
Often Topaz gas - liquid inclusions and fissures, with inclusions and cracks will affect the value of persons.
3. Processing
Topaz quality of the glass should have a clear gloss, and attention should be paid when processing can not be engraved with pearl necklace its major surface parallel to the direction of cleavage, it would be difficult to carry out polishing, will affect the value of precious stones.
4. Weight
Although Topaz for the mid-precious stones, the weight of the larger more common, but, like other precious stones, the greater are the more precious.
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