Chelsea filter
Its characteristic is that the color filter can only pass dark red and yellow-green light, and the Charles color filter is composed of two kinds of color filters. While all other light is absorbed. Charles filter was first used to distinguish natural emeralds from their imitations, because emeralds are red under the filter, while other green imitations are still green. In addition, the detection of artificially dyed gemstones and synthetic gemstones is also practical. For example, dyed jade bracelets and blue glass are red under the color filter, but some gems are not obvious under the color filter. For example, the color change of dyed quartzite is not obvious under the color filter. Therefore, the identification results of Charles filter are generally for reference only.
Because of its special lens, the third generation Charles filter. It is made of a kind of glass that never fades, so there is no need to worry that one day the dyed gem will be out of sight. Moreover, this special glass itself deepens the color filtering effect, which can also be seen for some very light dyes. In addition, a set of 30 times wide-angle optical gemstone magnifying glass is added, which is more convenient for collectors to observe the internal structure of jade bracelets and gemstones, the quality of carving technology and so on. Optical characteristics: transmitting crimson light and a small amount of yellow-green light, absorbing green light and other colors. Because it has the characteristics of transmitting colored light and absorbing colored light, it provides great help for me to identify various dyed green gems and blue gems, especially the dyed skin of Hetian jade and the dyed skin of antique jade, which saves collectors a lot of opportunities to be fooled.
2. 10 times magnifying glass:
In fact, 10 magnification magnifying glass is an essential tool for identifying gems. 10 Magnification Magnifier is used by quality inspectors when identifying various items. It consists of three lenses. The qualified 10 magnification magnifier should have high definition, which can eliminate the spherical aberration and chromatic aberration that affect the observation of gems. When in use, hold the magnifying glass in one hand and put it in front of one eye, and hold the jewelry holder with the index finger and thumb in the other hand (if it is bare stone, use gem tweezers) and approach the magnifying glass until the eye can clearly observe the gem. For loose diamonds, carefully clamp them with tweezers to prevent them from falling. The average 10 times magnifying glass is about tens of yuan, and the better one is only a few hundred yuan.
3. Electronic balance:
Different gems have different densities, which are used to measure the specific gravity of gems. For example, the ratio of ruby to sapphire is about 4, that of jadeite bracelet is 3.34, and that of nephrite is 2.95. Sometimes, it is very effective to measure the proportion of gems, but it is limited because it is too big to carry around.
4. Gem microscope:
Widely used, gem microscope is generally one of the necessary identification and testing instruments in gem laboratory. The appearance and internal characteristics of a gem can be clearly seen by magnifying it with a gem microscope. Gem microscope observes gems by using the working principles of dark field illumination, bright field illumination and vertical illumination through the built-in light source. The magnification is generally 10 to 70 times, which plays a great role in distinguishing natural gemstones from synthetic gemstones and imitation gemstones, and is also very effective in observing the purity of gemstones. In the gemological professional appraisal room, you can also measure the approximate refractive index and absorption spectrum of local gems with a gem microscope, as well as the micrographs of gems. Because of its relatively high price, it can be equipped according to the actual situation.
5. Strong flashlight:
Convenient to carry, and simple to operate. Essential tools for employees in jewelry industry.
These instruments are also available in various appraisal centers, and the above instruments are commonly used in gem appraisal. But in real life, it is impossible for me to take these instruments to the jewelry market to measure, and then distinguish the types and authenticity of gems. Therefore, it is very important to cultivate the first impression for jewelry appraisal. In other words, when you see a gem, you should be able to basically determine what it is. This is a feeling that needs temporary experience accumulation. Many sellers have also cultivated this ability in their temporary business. For example, some jade bracelets have not received any training, but they have accumulated considerable experience in jade bracelet identification in the first line of jade bracelet trading, and they can identify the authenticity without borrowing any instruments. Some professional jewelry appraisers are ashamed of this insight.