There are two kinds of fake rubies: the first is to pass the low-grade rubies off as rubies, and all fake rubies do not have the unique color of rubies.
The second is artificial ruby. Artificial ruby is very similar to natural ruby in terms of specific gravity, hardness and color. Intuitively, artificial rubies have uniform texture, no natural impurities, even and positive color, often large particles and lack naturalness.
Because the market price of ruby is high, there are many artificial methods to improve the quality of ruby.
Ruby is one of the precious varieties in jewelry. Ruby is bright in color, and under the illumination of light source, it can reflect beautiful and moving six-ray starlight, commonly known as six lines, which is caused by the special crystal structure of ruby and its unique optical phenomenon. Ruby is transparent, translucent and opaque, and its colors are water red, pink, pigeon blood red and rose red.
distinguish
First, artificial glass or other substances are filled in the cracks of ruby. This kind of treatment, there is no professional appraiser, and it is difficult to identify only by appearance.
Second, the upper end of the sandwich ruby is a transparent layer of natural corundum, and the pavilion at the bottom is a synthetic gem. From the above, you can see the natural inclusions, which makes people mistakenly think that it is a natural ruby.
3. In addition, there is a method of flame firing. Colorless corundum is put into chemical raw materials containing color-developing elements, and then the color-developing elements are heated at high temperature to make them penetrate into the surface of the gem, so that the colorless corundum becomes ruby.
But the color only reaches the surface of the stone, so the stone can't be cut or polished again, otherwise it will lose its treated color.
Extended data
Synthetic gems:
1900, scientists produced 2 g ~ 4 g rubies by melting alumina and adding a little chromium oxide. By the late 20th century, the output of rubies and sapphires could reach10g.
Artificial ruby has a high hardness, which is often used to make bearings for clocks and watches, and can also be used for solid-state lasers. Artificial sapphire can be used to make optical instruments because it can pass ultraviolet light and visible light.
Wynnell method
Compared with manual optimization of ruby, synthesizing ruby is the most troublesome problem. The earliest synthetic ruby was first invented by French chemist Wynyer. A device called Wynyer furnace was made of alumina powder. This artificial ruby has flooded the market. People not only use it to make some cheap decorative jewelry, but also regard it as a natural ruby.
Flux method
1963, Chatham Company of the United States synthesized a new synthetic ruby called Chatham Ruby by flux method. Ruby synthesized by these flux methods is more similar to natural ruby in appearance, so it is more deceptive.
It is difficult for most ordinary investment collectors to distinguish the microscopic characteristics between imitation rubies and natural rubies. Therefore, it is best to ask the relevant appraisal institutions for detailed appraisal.
Hydrothermal method
Ruby synthesized by hydrothermal method is more difficult to identify than ruby synthesized by flux method. Among them, the most important distinguishing feature is still the existence of seed crystal; In addition, sometimes you can see some "crumb-like" inclusions; Others have some microwave-like textures. If we can't find these features, we can only rely on more sophisticated large-scale instruments, such as infrared spectrometer and electron probe instrument.
Baidu Encyclopedia-Ruby (red and pink corundum)