Identification of Diamonds Diamonds are the hardest natural substances. A diamond can carve any other gem, but no other gem can carve a diamond. You can also use the "standard hardness tester" to score, and any hardness below 9 degrees is a fake diamond. Diamonds are also lipophilic. If you draw a line on the surface of a diamond with a pen, it will become a continuous straight line, while other gems will break intermittently. The above methods have certain reference value for identifying diamonds. You can also observe it through a magnifying glass with a magnification of 10. Under the magnifying glass of 10 times, you can see that most diamonds have triangular growth lines, and the surface of diamonds has "red, orange and blue" fire light. Radiant. The most accurate and reliable method is to measure the thermal conductivity data with a "thermal conductivity meter" to distinguish between genuine and fake diamonds, but the "thermal conductivity meter" is expensive. ……& gt； & gt& gt The eight most famous diamonds in the world are noble and luxurious ornaments. At present, it is not uncommon to substitute or pass off diamonds with cheap gems, artificial gem and even glass. Common fake diamonds are as follows: ① Zircon: Very similar to diamonds, it is the best substitute for diamonds. The identification method is that zircon has polarization and large birefringence. Observing the processed zircon prism surface with a magnifying glass of 10 times, it can be seen that the bottom edge line has obvious ghost, but the diamond has no ghost phenomenon. (2) Glass: The refractive index of glass is very low, and there is no flickering color light like diamonds; Especially when it sinks into the water, the glass product loses its luster and immediately shows clues. (3) Soviet diamond: cubic zirconia, first developed by the Soviets, hence the name. Soviet diamond is a synthetic compound, but it is very close to natural diamond in dispersion and refractive index, and it also has the attractive appearance of "fire" light. But its hardness is low (8.5), so it can be distinguished from diamonds. Moreover, the thermal conductivity is much lower than that of diamond, so it can be identified and distinguished accurately by "thermal conductivity meter". ④ Crystal: Although crystal is a transparent crystal of natural minerals, it looks like a diamond after processing, but it lacks the colorful light of diamond. ……& gt； & gt& gt player story: the recognition of the amazing love between Ruby and Crystal Girl; There are "ten Hong Jiu cracks" in natural gemstones, and natural rubies without any flaws and cracks are extremely rare. Artificial rubies have the same color, few internal defects or crystal inclusions, and are clean and large. As a precious gem, natural rubies over 3 carats are very rare in the market. If you encounter a big ruby, you should pay attention, because the value of natural ruby is thousands of times higher than that of artificial ruby. A little carelessness will "take medicine." Natural ruby has a strong "dichroism". The so-called dichroism means that there are two colors of red and orange red from different directions. If there is only one color, it may be red spinel, garnet or red glass. Red spinel and natural ruby are very similar, and they are most easily confused, so be very careful. Extension of sapphire identification: The color of natural sapphire in platinum is often uneven, and most of them have a straight growth line. Artificial sapphires are of the same color, and their growth lines are arc-shaped strips, and they are often breadcrumb-shaped or beaded bubbles in the body. Natural sapphire also has obvious dichroism, one direction is blue, and the other direction is blue-green. Other gemstones are different in color from natural sapphires and can be distinguished. In addition, the simplest method can be hardness measurement. Natural sapphires can carve traces on topaz, while other sapphires are difficult to carve traces on topaz. Therefore, when buying jewelry, if there is no instrument around, as long as there is a topaz, sometimes some problems can be solved. Identification extension of emeralds: amber ornaments in nature, there are many kinds of green transparent gems similar to emeralds, such as jadeite, tourmaline, fluorite, olivine, garnet, zircon, etc., among which tourmaline, fluorite and jadeite are easily confused because of their similar appearance. Visually, green jadeite is generally translucent, often in a patchy structure with interwoven fibers, while high-quality emeralds are transparent and crystal clear. Emerald hardness is 7.5-8, while fluorite hardness is very low, only 4. Emerald accounts for a small proportion, while fluorite, tourmaline and jadeite account for a large proportion. Zircon has strong dispersion and obvious ghost. In addition, there are artificial emeralds and green glass similar to natural emeralds. The biggest difference between them is that most natural emeralds have defects or inclusions, which shows dichroism. Of course, in order to distinguish strictly and correctly, it is best to use identification instruments such as optometry and polarizer. Identification of Cat's Eye In recent years, there is a kind of glass fiber cat's eye ring on the market, which is embedded in a gold or silver ring, making it impossible to tell the true from the false. The identification method is that when the torus is rotated, several light bands can appear at the arc top of the fake cat's eye at the same time, while there is only one real cat's eye. The fake cat's eye eyeliner is rigid, while the real cat's eye eyeliner is flexible. True cat's eyes are mostly brownish yellow or light green, while fake cat's eyes are varied in color, including red, blue and green. The identification of opal can be divided into black opal, white opal and yellow opal according to its color, of which black opal has the highest price. In order to improve the low-priced white or yellow opal, some people change its color artificially and become "black opal" in order to make high profits. The main method is to boil with sugar or inject plastic to make the white opal black. The identification method is that the specific gravity of opal is obviously different after boiling sugar or injection molding, and the specific gravity value becomes lighter when tested in water. The heating needle can also be used to test the injected opal. Natural opal can't be pierced by hot needles, but injected opal can be pierced, and it will produce the smell of plastic melting.