With the rapid development of the social economy, the jewelry industry has also rapidly prospered and revitalized, and now more and more people regard the collection of gemstones as a hobby, and some people regard the collection of gemstones as a kind of investment. However, most people do not know much about gemstones, which leads to some unscrupulous merchants to bring bad quality gemstones or even fake gemstones to cheat consumers. Therefore, both gemstone collectors and investors should learn some methods of gemstone identification.
In fact, it is very difficult to recognize the authenticity of gemstones by eyes only, on the one hand, it is very difficult to see some details clearly, on the other hand, there are some details that can only be seen under some special lights. Therefore, this time, the microscope becomes a very useful tool. In the following, we will show you how you can scrutinize gemstones with the help of a microscope. Of course, if you need an authoritative certificate of authenticity, you'd better find a real jewelry expert to make an authoritative appraisal of your gemstone.
Ⅰ. Do you need to use the microscope is different?
Generally speaking, the microscope used to observe gemstones is a binocular stereo microscope, and that kind of microscope used to observe gemstones has a slightly different structure compared with other microscopes, and its illumination equipment will be better in order to be able to better observe the internal details of gemstones. Overall, the structure of the microscope consists of three parts: the lens part, the illumination part and the mechanical part.
Ⅱ.What are the methods of illumination in a II microscope?
Most of the stereo microscopes used to observe gemstones are stereoscopic continuous zoom microscopes, in which a three-dimensional image of the gemstone can be seen under the microscope. And also continuous magnification can be realized to help the observer see the magnified image of the gemstone more clearly, generally speaking, their magnification is between 10x and 60x. In addition, there are many different types of illumination methods for gemstones, including a total of nine methods such as shielded illumination, bright field illumination, and scattered illumination. However, the five most commonly used methods are dark field illumination, bright field illumination, oblique illumination, top illumination, and horizontal illumination. The following is a detailed description of these methods.
1. Dark Field Illumination
The so-called dark field illumination method means that the illumination light does not shine directly on the gemstone, but is reflected and then shines on the gemstone. The light does not enter the barrel of the objective lens. The advantage of this method of illumination is that if there are any cracks or inclusions in the gemstone, they will be clearly visible on the microscope. It is also the most commonly used method because the bright light does not enter directly into the objective lens, which also facilitates the observer to observe the gemstone for a long period of time.
2. Bright Field Illumination
In contrast to the dark field illumination method mentioned above, the bright field illumination method requires that the light be directed at the gemstone and reflected directly into the observer's field of view after being refracted by the gemstone. This type of illumination allows the observer to see the color bands within the stone as well as the natural growth patterns of the stone. However, it is not suitable for long periods of time as the intense light is reflected directly back to the observer's eyes.
3. Oblique Illumination
Oblique illumination is the process of directing light obliquely towards a gemstone and reflecting it back to the human eye. This method of illumination helps to visualize the thin-film effect produced by the internal envelope of the stone. The thin-film effect of a gemstone, also known as the thin-film interference effect, simply means that the light will emit colorful rays of light through the clefts of the gemstone.
4. Top Illumination
The top lighting method, in which the light source on the bottom surface is turned off, leaving the light coming down from above, which is also reflected back into the human field of vision, is ideal for observing the characteristics of the surface of a gemstone. For example, color, cracks and spots.
5. Horizontal Illumination
Horizontal illumination is even simpler, as it only requires that the stone be illuminated from a horizontal angle. The observer is looking at the stone from above. This method of illuminating the gemstone allows you to clearly see the inclusions within the gemstone and whether or not there are air bubbles present within the gemstone.
Ⅲ.What is the actual operation procedure of Ⅲ microscope?
- Wipe the gemstone to be observed as well as the observation eyepiece clean first, in order to prevent the dirt on the surface of the gemstone from interfering with the observation during the subsequent observation.
- Clamp the gemstone onto the tweezers that hold it in place to prevent it from moving during observation.
- Plug in the power supply of the microscope and turn on the light source, then adjust the eyepiece distance to a suitable position for observation.
- Adjust the focal length of the microscope according to the actual situation, until you see a clear image of the gemstone. Here again, you can choose different light source irradiation methods mentioned above, such as dark field irradiation method, horizontal irradiation method and other methods to observe the surface or external features of the gemstone.
- At this time, adjust the objective lens of the microscope, magnify the imaging of the gemstone, so that more details can be observed.
- After all the observations are finished, make a record of the gemstone can be removed and then restore the eyepiece and objective lens of the microscope.
- Turn off the power and put all the accessories back to their place.
