Green-carbon-copper-zinc pendant This convex gem is set in yellow metal and matched with blue-green moonstone. The appearance of the central main stone is very attractive: it has the appearance of malachite-like grape ball structure, and it is a translucent to opaque fibrous structure. The bright blue-green color of this mineral is the result of typical copper coloring. The refractive index of the sample is 1.63- 1.75, and there is a scintillation reaction with poor refractive index of carbonate on the refractometer. The back of the gem was tested with dilute hydrochloric acid and proved to be a carbonate gem. Because gems are inlaid and opaque, the conventional gemological detection methods are limited, and further tests are needed to identify gems. X-ray fluorescence spectrum shows that the main components of the gem are zinc and copper, and a small amount of lead is also contained. The spectrum shows that its chemical composition is very close to that of green carbon copper zinc ore and sphalerite. Because of its high copper content, this gem is considered to be goldenrod. This is the first time to see green carbon steel zinc ore used in jewelry. Green carbon steel zinc ore is soft (Mohs hardness 1-2 degrees) and brittle. There are traces of repair on this jewelry, and a small piece can be seen peeling off at the top of the raised gem, leaving traces of glue adhesion. In India, there is a kind of green convex round gem, which is sold at the price of emerald. However, its appearance is completely different from that of emerald. When you zoom in, you can see the granular to flaky structure, and this substance is composed of many minerals, and you can see different shades of green. The specific gravity of this convex round gem is 2.89. Because its polycrystalline structure and specific gravity are not enough to be used as the main basis for identification, the new technology is adopted to study this gem. The Raman spectra of five points on the gem show that the substance that produces different green tones is muscovite. In order to explore the cause of green, it was analyzed by X-ray fluorescence spectrum, and finally it was shown that it contained a lot of silicon, aluminum, potassium and a small amount of calcium, strontium, iron and chromium. The green color of mica is due to the existence of chromium, so it should belong to chromite mica minerals. The diagenesis of this mineral is composed of strongly polychromatic crystals in different directions, which leads to different shades of green appearance. This raised round gem contains rare orange and white lines, which can be seen by Raman spectrum analysis. They are rutile and dolomite respectively. At the bottom, a saturated green circle can be observed in the outer ring. This phenomenon is probably green Joban oil. After infrared spectrum test, it is confirmed that this gem has been treated by oil immersion. Three unusual synthetic rubies weighing 3.2 1 carat, 4.49 carats and 7. 1 carat were detected in the laboratory in Guberlin, Switzerland. It is found that the flux is distributed along the crack and the needle-like inclusions are linear. X-ray fluorescence spectrum analysis shows that it contains 0.54%-0.92% of Cr2O3, 0.06%-0. 1% of Te2O3 and 0.0 1%-0.03% by weight. In addition, it also contains 0.02%-0.03% zirconium dioxide, which has no correlation with inclusions, and there are no other heavy metal elements such as aluminum or tungsten in the gem. The internal growth structure of flux residue and the weight percentage concentration of trace elements were analyzed. We can know that these gems are rubies synthesized by flux. But the overall characteristics of these synthetic rubies are slightly different from those of ordinary synthetic rubies. It has inclusions (commonly known as "raindrop-like" inclusions) similar to those of synthetic rubies produced in Kashan, and any commercially produced synthetic ruby does not contain zirconium dioxide. Natural ruby occasionally contains zirconia, but it is always associated with zircon crystals. Moreover, these rubies contain calcium and iron, but lack titanium and vanadium, which is very unusual in the synthesis of rubies by flux method. Usually, heavy metals such as lead or tungsten often appear in synthetic rubies from Chatham, Duross or La Mora, but not in this batch of synthetic rubies. Although it is not clear whether these synthetic rubies belong to new synthetic rubies, under the observation of hand-held magnifying glass or microscope, these unusual synthetic rubies can still be judged by the presence or absence of flux. Chemical analysis can detect the existence of zirconium and the distribution of other trace elements to judge their synthesis and natural identity. Since 1880, the diffusion treatment technology of sapphire has been made public. It is generally believed that the blue color is caused by the diffusion of titanium to the surface of human gemstones, and cobalt is also used to replace titanium for diffusion treatment. The blue color of this gem is very moving, but the blue color processed by this diffusion technology is very thin. It is difficult to see under a magnifying glass of 60 times, so there has never been such a product on the market. Not long ago, two blue sapphires weighing 2.23 carats and 2.74 carats respectively were sent to GIA Gemstone Appraisal Center. Among them, the 2.74-carat sapphire has the following characteristics: in diiodomethane, the color is obviously concentrated on the edge line of the gemstone facet, and the uneven block color indicates that it is a diffused sapphire; Another sapphire weighing 2.34 carats is deeper and brighter than the former in appearance, and its refractive index exceeds the limit. Three typical broad absorption bands caused by diamond elements can be seen under the mesa-shaped spectroscope. After magnification, no inclusions can be seen, but there are countless small spots near the surface, and some faceted ridges are lighter in color. Because the emissivity of the carved gemstone is much higher than expected, it is found that a large amount of cobalt is concentrated on the surface of the gemstone by Raman microspectroscopy analysis. Obviously, the high refractive index of the gem itself is caused by cobalt. This phenomenon is particularly easy to appear on the red corundum gem treated by thermal diffusion. In addition, it is also common in topaz, which is blue-green because of cobalt impurities on its surface. This topaz is often suspected to have been diffused, but it is uncertain whether it has been diffused. Like topaz, the blue surface of this 2.23-carat sapphire is almost invisible. It is so thin that even a small crack or tiny scratch can expose the colorless area inside the gem, so it is impossible to confirm whether the gem has been treated or just reacted with cobalt on the surface. This kind of sapphire has caused many questions, and it is uncertain whether this kind of sapphire has entered the market in large quantities. Irradiated color-changing fluorite At AGTA Jewelry Fair in 2002, a batch of irradiated fluorite aroused great interest. The raw stone of this fluorite is produced in Minas province, Brazil, and it is pale yellow before irradiation. This gem changes color after irradiation, showing dark blue in sunlight and reddish purple in incandescent light. According to the standard gemmological determination, the specific gravity of this gem is 3. 19 and the refractive index is 1.43 1. There is no fluorescence reaction under long-wave ultraviolet light and short-wave ultraviolet light, and there is moderate pseudo-birefringence reaction. The absorption line of 570nm can be seen under the desktop spectrometer, and it is red under the Charles filter. Under the microscope, it can be found that it contains two-phase inclusions. There was no brown test in the laboratory, but the irradiated fluorite displayed at the jewelry show did not fade after a few days. Fluorite has been treated by irradiation technology for many years, but the special feature of this irradiation treatment lies in its bright body color and discoloration. Imitation of starlight gemstones In recent years, a fake method of imitating starlight gemstones by directional manual scoring is often applied to convex gemstones, but this fake method is very easy to identify. First of all, GEM lacks directional inclusions; Secondly, directional scratches are common on the surface of gemstones. In addition, the star lines of these starlight gems are incomplete, irregular or incorrect in direction, curved and asymmetrical, and some of them are inconsistent with the mineral crystal system. When taking pictures of these gems. Another method is found to help identify these artificial starlight phenomena: when shooting artificial starlight gems, focus the camera below the convex gem surface, and the starlight phenomenon is the clearest at this time. When shooting natural starlight gemstones, the focal length of the camera is aimed above the surface of the raised gemstone.