First, the texture of jewelry, there are two kinds of texture descriptions on platinum jewelry, some are English Pt and some are Chinese "Platinum";
The second is the composition of jewelry. If there is "99" on the platinum jewelry, it means that the platinum content is 99%;
Third, the origin of jewelry, jewelry manufacturers everywhere have their own unique seals. These seals, like the trademarks of other industrial products, are essential for the first jewelry, and counterfeiting is absolutely not allowed, because it is not only a symbol of producers, but also a symbol of consumers. It is mainly stainless steel or silver jewelry that is easily confused with real platinum jewelry. Stainless steel jewelry is similar to platinum jewelry in the new era, with gray color and bright luster. However, its white color is gray-black, bright and false, not durable and easy to wear. Silver jewelry is soft and easy to wear; Light in weight, silvery white in color, whiter than platinum, and easy to turn black when used for a long time. In addition, from the seal point of view, stainless steel jewelry has no seal or the seal is vague, and the seal of silver jewelry is different from that of platinum jewelry. The main varieties of gold jewelry are rings, earrings, necklaces, bracelets and brooches. When buying gold jewelry, we must first identify its authenticity in the following ways:
Check the weight. Compared with metal ornaments of the same size, gold is heavy.
Second, listen to the sound, throwing gold ornaments on the ground will make a "poof-poof" sound, and the low content will sound crisp.
The third is to look at the color. Gold jewelry has a lasting luster, and the jewelry with high gold content is red, while the jewelry with poor gold content is yellow.
The fourth is to test the hardness. The higher the gold content of jewelry, the softer it will be. If you scrape with a hard needle tip, there will be obvious marks. The sign of low gold content is vague.
Fifth, the hand is bent. Real gold is soft, easy to bend when bending by hand, but not easy to break, while ornaments with color difference are easy to break and not easy to break. The sixth is to use fire. When the ornaments are burned with fire, the real gold will not change color, but the fake gold will lose its luster and even become black and purple after burning. Seventh, acid test. Gold is insoluble in hydrochloric acid, sulfuric acid and nitric acid, while other metals will change when they meet three acids. Asia is rich in jadeite. Its delicate and beautiful green color and excellent texture are deeply loved by consumers in Southeast Asia, Hong Kong, Macao, Taiwan, Japan and Chinese mainland, and are regarded as the top grade of jewelry. In fact, jadeite also has several variegated colors, such as white, red and black. Green jade is of course genuine. High-quality jadeite is bright turquoise, just like autumn water. Emerald is translucent or opaque, with bright luster, and there are naturally formed irregular color blocks in green, which is called color source. There are tiny particles in it, which are fibrous, flaky or star-shaped and shiny. This is an emerald, many imitations are not available, and it is a sign to judge whether it is true or not. There are many green gems, but emeralds are unique. The whole piece of jade is thick green and has a unique charm.
Jade has a specific gravity of 3.3 and a hardness of 6.5~7. There are two kinds of fake jadeites. One kind is green low-value gems, such as Australian jade, Henan jade, green agate, Dongling stone and so on. The other is glass products. Among the low-value gems, Australian jade is green and yellow, and the whole jade is even in color, colorless and emeraldless. Henan jade green is light gray, with uniform color, no obvious color source and shape, and its specific gravity is 2.65, which is smaller than that of jadeite. The green of Dongling Stone is dark, the color is dotted, and fish scales are shining in the green. Green agate is artificially dyed agate, which is blue in green, uniform in color, emerald-free and delicate in luster, with a specific gravity of 2.65, which is smaller than that of jadeite. Green glass is green and dull, and its hardness is 5.5~6. Glass plates can't be marked, but jadeite can. To judge the quality of a diamond, we usually look at its color, weight, cleanliness and whether the cut surface can show bright characteristics. Consider whether a diamond is worth buying. The first condition is that this diamond has not been set. Because the inlaid gems can't accurately identify their grades. Different forms of inlay can make a diamond look brighter or darker than itself; Moreover, the claw marks on the inlay can hide the defects on the diamond. Diamond is the hardest stone in nature, but if the force is not accurate when it is inlaid or disassembled, it will damage the edge of the diamond and affect its value. If the diamond is inlaid at the time of purchase, remember to disassemble the diamond during identification, so as to identify its integrity, texture and value more accurately. Dirty diamonds will turn yellow and dark. Generally, once every six months, the diamond ornaments are put into a special cleaning solution and cleaned on an ultrasonic cleaning machine to keep the luster. The identified diamonds should be at least clean. After disassembly and cleaning, it is necessary to identify the grade and color of the diamond.
If you observe a diamond in sunlight or yellow light, it will give off bright light. The correct way is to put the diamond in a pure white light source without ultraviolet light and observe it carefully with a magnifying glass 10 times. When buying diamonds, it is not easy to identify them with the naked eye. Round cut diamonds can reflect a lot of light from the desktop. So you can't see whether there is any flaw below from above, but only through the bottom of the sharp point. Laymen should pay attention to this. The American Gemological Institute classifies diamonds into several grades in color: D to F are colorless, that is, 99 and 98 colors; G to 1 is almost colorless, all of which are top grades; However, the color below 1 level is light yellow or light yellow, that is, less than 95 colors. In terms of quality, perfection is a first-class product, √√S 1 is a first-class minimal defect, and √√√ S2 is a second-class minimal defect. These diamonds are worth buying and collecting. Natural gemstones have "ten Hong Jiu cracks", 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.
Supplementary explanation of ruby
Ruby's English name is Ruby, which comes from Latin Ruber, meaning red. The mineral name of ruby is corundum.
The chemical composition of ruby is alumina (Al2O3), which is red to pink due to the trace element chromium (Cr3+). It belongs to the tripartite crystal system. The crystal shape is often barrel, short column, plate and so on. Aggregates are mostly granular or dense blocks. Transparent to translucent, glass luster. The refractive index is 1.76- 1.77, and the birefringence is 0.008-0.0 10. Dichroism is obvious, and it is not isotropic. Sometimes it also has a special optical effect-starlight effect, which will reflect charming six-shot starlight under the irradiation of light, commonly known as "six lines". The hardness is 9, and the density is 3.95-4. 10g/cm3. No cleavage, cleavage development. Ruby emits red and dark red fluorescence under long-wave and short-wave ultraviolet irradiation.
Among the reds of rubies, the most valuable one is the one with the strongest color, called' pigeon blood', which is very valuable. This bright and intense color can almost be called crimson, and you can see the true face of ruby at a glance. Unfortunately, most rubies are light in color and have a pink feeling, so the rubies with pigeon blood tones are more valuable. In addition, because ruby is full of strong vitality and rich colors, people in the past thought it was the incarnation of a dead bird and had ardent illusions about it. Natural rubies are scarce, and high-quality rubies are only produced in Myanmar, and the output is gradually decreasing. It can be said that it has almost declined, and big stones no longer appear.
Evaluation and purchase of rubies. The primary evaluation and purchase factor of ruby is color, followed by weight, transparency and purity. Generally speaking, faceted rubies with pure color, large particles, transparency, no or few inclusions and defects, fine processing and symmetrical parts are excellent products. Burmese rubies are mostly pigeon blood red, with uniform color, large transparency, large particles and few defects and cracks. Ruby in Sri Lanka is light in color, and the main variety is Star Ruby. Thailand pointed bamboo ruby, deep red, not too bright, relatively clean. Ruby is fragile, so be careful when wearing it. Natural sapphires are often uneven in color, and most of them have a flat 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.
Supplementary explanation of sapphire
Sapphire's English name is sapphire, which comes from the Latin Spphins, meaning blue. The mineral name of sapphire is corundum, which belongs to corundum family. In the gem world, all kinds of gem-grade corundum except ruby are collectively called sapphire.
The chemical composition of sapphire is alumina (Al2O3), which is blue because it contains trace elements of titanium (Ti4+) or iron (Fe2+). It belongs to the tripartite crystal system. Crystal shape is often cylindrical, short column, plate and so on. The geometric shape is mostly granular or dense block. Transparent to translucent, glass luster. Refractive index 1.76- 1.77, birefringence of 0.008, strong dichroism. Not an isotropic body. Sometimes it has a special optical effect-starlight effect. The hardness is 9 and the density is 3.95-4. 1g/cm3. No cleavage, cleavage development. It can produce beautiful starlight under certain conditions, which is called "starlight sapphire".
Sapphire can be divided into blue sapphire and brilliant (non-blue) sapphire. Indian "cornflower blue" is the best color. It is said that sapphire can protect kings and monarchs from harm, and it is called "the stone of kings". Sapphire has been designated as the "September Birthstone" by the international gem circle, symbolizing kindness, loyalty and loyalty. Sapphire is one of the five precious and high-grade gems in the world.
Evaluation and purchase of sapphire. The evaluation and purchase factors of sapphire are color, weight, transparency and purity. Sapphire is characterized by uneven color, undeveloped polycrystalline twins and strong dichroism. Sapphire produced in Myanmar is bright blue (titanium color) because the inclusion can produce six or twelve starlight. Sapphire from Kashmir, India, is a kind of high-quality sapphire, which is cornflower blue and indigo blue with bright color. Sapphires from Sri Lanka, Thailand, China and Australia also have their own characteristics. Sapphire is fragile, so you should avoid bumping and bumping when wearing it.
In nature, there are many kinds of green transparent gemstones similar to emeralds, such as jadeite, tourmaline, fluorite, olivine, garnet, zircon, etc. Among them, tourmaline, fluorite and jadeite are easily confused because of their similar appearance to emeralds. 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. There is a kind of glass fiber cat's eye ring in the market, which is set in a gold ring or a silver ring, so people can't tell the truth 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 line is rigid, while the real cat's eye line 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.
Golden emeralds are second only to diamonds and red sapphires in hardness. Golden emeralds and various changeable stones and opals are not only very beautiful, but also very expensive, because they are extremely rare. Opal is the color-changing effect of emerald with developed vacuum inclusions after Kapson cutting.
Supplementary explanation of opal
Gold emerald is an alumina containing beryllium, and its chemical molecular formula is BeAl2O4. It belongs to orthorhombic system. Crystal morphology is often short columnar or plate-shaped. Opal has many colors, such as honey yellow, brownish yellow, wine yellow, brownish yellow, yellowish green, yellowish brown, grayish green and so on, among which honey yellow is the most precious. Transparent to translucent. The glass is greasy and shiny. The refractive index is 1.746- 1.755, and the birefringence is 0.008-0.0 10. Dichroism is obvious, the dispersion is 0.0 15, and it is not isotropic. The hardness is 8.5, and the density is 3.71-3.75g/cm3. Shell fracture.
Opal is named after its smooth and rotating color like cat's eye, so it is also called' Opal' in English literal translation. Only emerald cat's eyes can be directly called cat's eyes. Opal has the color of honey, especially a light mark, which will reflect to both sides and become' three light marks', so its price is judged to be very high. In terms of color, cream color and lemon color are not as good as honey color, and brown and gray have lower evaluation. Put the cat's eye in the light. You can display a clear light, and when you turn it, the light bar will shake left and right, which is cat's eye discoloration.
In addition to emeralds, there are other kinds of gems that can show the same luster and deformation effect as cat's eyes. Such as calcium carbide, apatite and blue crystal. There is also a mineral [Tiger Eye Stone] which has the same effect because of its fibrous structure of asbestos, but it can't be compared with the golden green cat's eye. The crown of the king of Iran is inlaid with a yellow-green cat's eye, weighing 147.7 carats. Pearls are divided into natural pearls and cultured pearls, and cultured pearls are divided into seawater pearls and freshwater pearls. Natural pearls are low in output and expensive; Moreover, cultured pearls can be produced in large quantities, so the price is much lower. The main difference between them is that natural pearls and cultured pearls have no nuclei. The inner core of natural pearls is often just some sand or parasites, or even no inner core. However, the inner core of cultured pearls is artificially made large round beads, so the outer coating is thin. On the body surface, natural pearls rarely roll because of their random growth environment and poor roundness. The inner core of cultured pearls is round, so the roundness of pearls is better. Natural pearls are transparent because of their long growth time, delicate texture, thick nacre, smooth skin and few "convex bubbles". The cultured pearls are thin in layer, rough in texture, "waxy" in luster, and have some uneven "bubbles" on the surface, so the transparency is poor. If it is a perforated pearl, observe the hole carefully with a magnifying glass. If it is a cultured pearl, you can generally see a brown boundary inside the pearl, which is the boundary between the inner core and the pearl layer that grows later.
Imitation pearls often appear in the market, which are generally made of glass beads coated with fish scale powder or silver powder. Their luster is obviously different from that of real pearls, and their weight is also different, which can be recognized by people with a little experience. If you scrape off a nail or a knife, the true face of Lushan Mountain will be revealed immediately. Olivine is a kind of low-grade gem, with yellow in green, similar to olive. The most common counterfeit olivine on the market is made of stained glass. The main difference between the two is that olivine has obvious "double shadow", while glass does not; Crystal inclusions are often seen in olivine, and only bubbles are contained in glass. Olivine has a specific gravity of 3.5 and a hardness of 7, which is greater than that of glass (2.6) and hardness (6).