If someone says that a gem can be recognized at a glance, you would think he is talking about it. Although not all gems can be identified at a glance, there are indeed some gems that can be easily identified with the naked eye.
The color of some gems is very stable and typical, which makes it possible to identify them with the naked eye. So which gemstones are so typical that they can be recognized by the naked eye? To clarify this problem, we must first understand how the color of the gem is formed.
We all know that natural light is a mixture of colorful lights of different wavelengths. Our naked eyes cannot see that some of the wavelengths that make up natural light are missing, and the situation is different. When the remaining wavelengths of light are combined, it seems impossible to be white, but to show a certain color. The reason why gems show various colors is that some special elements inside absorb part of the light.
Not all elements absorb light. There are very few elements that can absorb light, such as Fe, Cu, Mn, ของ, ฯลฯ. These elements are called color-causing elements. If there is no color-causing element in a gemstone, it cannot absorb any light. What color will the gemstone look like? ใช่, white or colorless, gems will look like white crystals or white moonstones. ในทางกลับกัน, if a certain element in the gem strongly absorbs light, or even absorbs all the light, the gem looks black. If the color-causing elements in a gemstone only selectively absorb part of the light, the gemstone will show a certain charming color.
Under normal circumstances, color-causing elements are present in gems in the form of trace impurities, and these gems are called other colored gems. A very important feature of other colored gemstones is that the original colorless gemstones will show different colors when they contain different color-causing elements. ตัวอย่างเช่น, beryl is colorless when pure. When traces of different color-causing elements enter the beryl, the beryl will show different colors such as green, สีฟ้า, and pink.
Similarly, pure corundum is also colorless. When a small amount of Cr element enters, it will appear red, namely ruby; a small amount of Fe and Ti enters, it will appear blue; a small amount of Mn can make it appear orange; and a small amount of V can Make it purple…
It is not an impurity element, but the main chemical composition that makes up a certain gem. The color of a gem cannot be as impermanent as other colored gems. Such gems are called white gems. The color of white gemstones is very stable and the variety is relatively single. The color only has a change in depth and intensity, but not a big change in hue. The main thing we can recognize with the naked eye is this type of gem.