Real white gold jewelry is made of the metal platinum. Metal platinum is also called platinum, its chemical symbol is Pt, its specific gravity is 21.45, and its Mohs hardness is 4.3. Comparing the three precious metals of the same volume: platinum, gold, and silver, platinum is the heaviest and hardest in texture. Due to its small natural reserves, difficulty in mining, and stable chemical properties, platinum is a metal material more valuable than gold. The texture of platinum jewelry is fine and slightly hard, not easy to wear, the color is light gray-white, light and elegant, the luster is bright and long-lasting, and it will not turn black after being used for a long time. Real platinum jewelry has a stamp on it, which is the main identification. The seal mainly includes the following contents:
The first is the texture of the jewelry. There are two texture descriptions on platinum jewelry, some are Pt in English, and some are "platinum" in Chinese;
The second is the jewelry. Composition, if there is the word "99" on platinum jewelry, it means that the platinum content is 99%;
The third is the origin of the jewelry. Enterprises that produce jewelry in various places have their own unique stamps, which are the same as the trademarks of other industrial products. Likewise, it is indispensable for jewelry and must not be counterfeited, because it is the identification of both the producer and the consumer. The main things that are easily confused with real platinum jewelry are stainless steel or silver jewelry. Stainless steel jewelry is similar to platinum jewelry when new, with a gray color and bright luster. However, its white color is gray-black, shiny and fake, and it is not long-lasting and is easily worn. Silver jewelry is softer in texture and easier to wear; it is lighter in weight and silvery white in color, whiter than platinum, and it tends to turn black after being used for a long time. In addition, judging from the stamps, stainless steel jewelry does not have stamps or the stamps are blurred, and the stamps of silver jewelry are different from those of platinum jewelry. The main types of gold jewelry include rings, earrings, necklaces, bracelets, brooches, etc. When purchasing gold jewelry, you must first identify its authenticity by:
Weigh the weight. Compared with metal jewelry of the same volume, gold jewelry is heavier.
The second is to listen to the sound. If you throw the gold jewelry on the ground, it will make a "pop" sound. If the gold jewelry has a low content, the sound will be clear and crisp.
The third is to look at the color. The luster of gold jewelry lasts for a long time. Jewelry with high gold content will be red, while jewelry with poor gold content will be yellow.
The fourth is to test the hardness. The higher the gold content of the jewelry, the softer it will be. If you scratch it with a hard needle tip, there will be obvious marks; if the jewelry has a low gold content, the marks will be blurred.
Fifth, the hand is bent. Real gold is soft and can be bent easily but not easily broken when bent by hand, while jewelry with different colors is easy to break but not easy to bend. Sixth, burn with fire. When jewelry is burned with strong fire, real gold will resist burning and will not change color, while fake gold will lose its luster or even turn black and purple after burning. Seventh is the acid test. Gold is insoluble in hydrochloric acid, sulfuric acid, and nitric acid, while other metals change when exposed to the three acids. Jadeite is abundant in Asia. Its delicate and beautiful green color and excellent texture are deeply loved by consumers in Southeast Asia, Hong Kong, Macao, Japan and mainland China. It is regarded as the top grade in jewelry. In fact, jadeite also comes in several variegated colors, such as white, red, black, etc. Of course, green jadeite is genuine. High-quality jadeite is bright and bright green, just like a stream of autumn water. Jadeite is translucent or opaque, smooth and bright, with naturally occurring irregular color patches in the green color, which is called the color source. There are small crystal grains inside, either in the shape of fibers, sheets, or stars, which are shiny and shiny. This is the jadeite nature, which many imitations do not have, and it is a sign of authenticity. There are many green gemstones, but the emerald nature is the unique characteristic of jadeite. The whole piece of jadeite is rich in emerald nature and has a unique charm.
The specific gravity of jade is 3.3, and the hardness is 6.5~7. There are two types of fake jadeite, one is green low-value gemstones, such as Australian jade, Henan jade, green agate, aventurine, etc.; the other is glass products. Among low-value gemstones, Australian jade is green with yellow flashes, and the whole jade is uniform in color, colorless, and non-emerald. Henan jade green is gray in color, uniform in color, and has no obvious color source or shape. Its specific gravity is 2.65, which is smaller than jadeite. The green color of aventurine is dark, its color is point-like, and there are flashes of fish scales in the green. Green agate is artificially dyed agate, green with blue flashes, uniform color, no jade, oily and delicate texture, and a specific gravity of 2.65, which is smaller than jade. Green glass is green and dull, with a hardness of 5.5~6. You cannot scratch the glass plate, but jade can.
To identify the quality of a diamond, it is usually based on its color, weight, cleanliness and whether the cut surface can express the characteristics of brilliance. Consider whether a diamond is worth buying. The first condition is that the diamond has not been set. Because the grade of an inlaid gemstone cannot be accurately identified. Different forms of setting can make the diamond look whiter or darker than itself; and the claw marks on the setting can better hide the flaws on the diamond. Diamonds are the hardest natural gemstones. However, if the force used when setting or disassembling is not accurate, it can damage the edges of the diamond and affect its value. If the diamond has been set when you buy it, remember to disassemble the diamond during appraisal to more accurately assess its integrity, texture and value. A stained diamond will turn yellow and dull. Under normal circumstances, diamond jewelry should be placed in a special cleaning solution and washed in a supersonic washing machine once every six months to keep it shiny. The diamonds that are appraised must at least be clean. After disassembly and cleaning, it is time to identify the grade and color of the diamond.
If you look at the diamond under sunlight or yellowing light, the diamond will sparkle and dazzle; but the correct method is to put the diamond under a pure white light source without ultraviolet rays and use 10 Observe carefully with a magnifying glass. When purchasing a diamond, it is not easy to identify it with the naked eye. A round cut diamond reflects a large amount of light coming in from the table. Therefore, it is impossible to tell from the top if there are any flaws underneath, only by looking through the pointed base. Laymen should pay attention to this. The Gemological Institute of the United States divides diamonds into several grades in terms of color: D to F grade are colorless, that is, ninety-nine or ninety-eight colors; G to 1 grade are close to colorless, all are top grade; and below grade 1 are slightly yellow or light yellow , that is, below ninety-five colors. In terms of quality, it is flawless and belongs to the first grade. √√S1 belongs to the first grade very slight flaws, and √√S2 belongs to the second grade very slight flaws. Diamonds of these qualities are worth buying and collecting. Natural gemstones are "ten red and nine cracked". Natural rubies without any flaws or cracks are extremely rare. Artificial rubies, on the other hand, have the same color, fewer internal defects or crystal inclusions, are clean, and have larger blocks. As precious gemstones, natural rubies exceeding 3 carats are very rare on the market. If you encounter larger rubies, you must pay attention, because natural rubies are hundreds of times more valuable than artificial rubies. If you are not careful, you will "Take your medicine".
Natural rubies have strong "dichroism". The so-called dichroism means that there are two tones of red and orange-red when viewed from different directions. If there is only one color, it may be a red spinel. Stone, garnet or red glass, etc.
Red spinel is very similar to natural ruby. The two are most easily confused, so special caution must be taken.
Supplementary explanation of ruby
The English name of ruby ??is Ruby, which comes from the Latin Ruber, which means red. The mineral name of ruby ??is corundum.
The chemical composition of ruby ??is aluminum oxide (Al2O3), which is red to pink due to the trace element chromium (Cr3). It belongs to the trigonal crystal system. The crystal shape is often barrel-shaped, short columnar, plate-shaped, etc. The aggregates are mostly granular or dense blocks. Transparent to translucent, glassy luster. The refractive index is 1.76-1.77, and the birefringence index is 0.008-0.010. Obvious dichroism, heterogeneous body. Sometimes it has a special optical effect - starlight effect, which reflects charming six-ray starlight when illuminated by light, commonly known as "six lines". The hardness is 9 and the density is 3.95-4.10 g/cubic centimeter. No cleavage, cleavage development. Ruby fluoresces red and dark red under long-wave and short-wave ultraviolet irradiation.
Among the red colors of rubies, the most valuable is the gem with the strongest color, called 'pigeon's blood', which is very valuable. This bright and intense color, which can almost be called deep red, reveals the true nature of the ruby. Unfortunately, most rubies are light in color and have a pinkish feel, so rubies with pigeon blood tones are more valuable. In addition, because ruby ??is filled with strong vitality and rich color, people in the past thought it was the incarnation of a dead bird and had enthusiastic fantasies about it.
The origin of natural rubies is very rare. High-quality rubies are only produced in Myanmar, and the output is gradually decreasing. It can be said that it has almost disappeared, and large stones no longer appear.
Ruby evaluation and purchase. The primary evaluation and purchase factor for rubies is color, followed by weight, transparency and clarity. Generally speaking, faceted rubies with pure color, large particles, transparency, no or few inclusions and defects, fine processing, and well-proportioned parts are considered top-grade. Burmese rubies are mostly pigeon blood red, with uniform color, high transparency, large grains, and few flaws and cracks. Sri Lankan rubies are light in color and the main variety is star ruby. Thai sharp bamboo pattern ruby, deep red, not too bright in color, relatively clean. Ruby is brittle and is afraid of being knocked or beaten, so you should be careful when wearing it. Natural sapphires tend to be uneven in color, with most having straight growth lines. Artificial sapphire has the same color, its growth lines are arc-shaped bands, and breadcrumb-shaped or bead-shaped bubbles can often be seen in the body.
Natural sapphire also has obvious dichroism, looking blue from one direction and blue-green when looking from the other direction. The color rendering of other gemstones is different from that of natural sapphires, and they can be distinguished accordingly.
In addition, the simplest method can be the hardness measurement method. Natural sapphire can carve marks on topaz, while other blue gemstones are difficult to carve marks on topaz. Therefore, when buying jewelry, such as those around you Without instruments, as long as you have a piece of topaz, you can sometimes solve some problems.
Supplementary explanation of sapphire
The English name of sapphire is Sapphire, which comes from the Latin Spphins, which means blue. The mineral name of sapphire is corundum, which belongs to the corundum family of minerals. In the gem industry, besides rubies, all other gem-grade corundums are collectively called sapphires.
The chemical composition of sapphire is aluminum oxide (Al2O3), which is blue due to the trace elements titanium (Ti4) or iron (Fe2). It belongs to the trigonal crystal system. The crystal shape is often cylindrical, short columnar, plate-shaped, etc., and the geometry is mostly granular or dense block. Transparent to translucent, glassy luster. The refractive index is 1.76-1.77, the birefringence is 0.008, and the dichroism is strong. Heterogeneous body. Sometimes there is a special optical effect - starlight effect. The hardness is 9 and the density is 3.95-4.1 g/cubic centimeter. No cleavage, cleavage development. Under certain conditions, beautiful six-ray starlight can be produced, which is called "star sapphire".
Sapphires can be divided into blue sapphires and vivid (non-blue) sapphires. The best color is "cornflower blue" produced in India. It is said that sapphire can protect kings and monarchs from harm, and is known as the "Emperor Stone". The international gem industry defines sapphire as the "birthstone of September", symbolizing love, loyalty and perseverance. Sapphire is one of the five most precious and high-end gemstones in the world.
Sapphire evaluation and purchase. Factors for evaluating and purchasing sapphires are color, weight, transparency and clarity. The biggest characteristics of sapphire are uneven color, lack of development of polycrystalline twins, and strong dichroism. Sapphires produced in Myanmar are bright blue (colored by titanium). Due to inclusions, they can produce six-ray or twelve-ray starlight. Indian Kashmir sapphire is cornflower blue, slightly purple indigo, bright in color, and is a high-quality sapphire. Sapphires produced in Sri Lanka, Thailand, China, and Australia also have their own characteristics. Sapphire is brittle and should be avoided from being dropped or bumped when wearing it.
In nature, there are many types of green transparent gemstones that are similar to emeralds. The more common ones are jadeite, tourmaline, fluorite, peridot, garnet and zircon. Among them, they look like emerald and are easily confused. The ones are tourmaline, fluorite and jade. Observed with the naked eye, green jadeite is generally translucent and often has a structure of interwoven fibrous spots, while high-quality emerald is transparent and crystal clear. The hardness of emerald is 7.5-8, while the hardness of fluorite is low, only 4. Emerald has a smaller proportion, while fluorite, tourmaline, and jade have a larger proportion. Zircon has strong dispersion and obvious double shadows.
In addition, there are artificial emeralds, green glass, etc. that are similar to natural emeralds. The biggest difference between them is that most natural emeralds have flaws or inclusions, and two colors can be seen. sex. Of course, it is best to use identification instruments such as refractometers and polarizers to make strict and correct distinctions.
There is a kind of fiberglass cat's eye ring for sale on the market, which is set on a gold or silver ring, making it difficult to tell whether it is genuine or fake. The identification method is that when the ring is turned, several light bands can appear at the top of the arc of the fake cat's eye, while there is only one real cat's eye. Fake cat eye eyeliner is dull, while real cat eye eyeliner opens and closes flexibly. The color of real cat's eyes is mostly brownish yellow or light green, while fake cat's eyes come in various colors, including red, blue, green and other colors.
Chrysoberyl is a gemstone whose hardness is second only to diamond and ruby ??sapphire. Chrysoberyl and variants of alexandrite and cat's eye, these three gemstones are not only very beautiful, but also very expensive because they are extremely rare. After the chrysoberyl, which contains well-developed vacuum-like inclusions inside, is cut by Caboson, the color change effect is the cat's eye stone.
Supplementary explanation of cat's eye
Chrysoberyl is a beryllium aluminum oxide with a chemical formula of BeAl2O4. It belongs to the orthorhombic crystal system. The crystal morphology is often short columnar or plate-shaped. Cat's eye stones come in various colors, such as honey yellow, brown yellow, wine yellow, brown yellow, yellow green, yellow brown, gray green, etc. Among them, honey yellow is the most valuable. Transparent to translucent. Glass to grease luster. Refractive index 1.746-1.755, birefringence 0.008-0.010. The dichroism is obvious, the dispersion is 0.015, and it is a heterogeneous body. Hardness 8.5, density 3.71-3.75 g/cubic centimeter. Shell-shaped fracture.
Cat’s eye is named because of its color that rotates like a cat’s eye. Therefore, it is also called ‘cat’s eye’ in English literal translation. Only chrysoberyl cat’s eye can be directly called cat’s eye. Cat's Eye has the color of honey, and its one light mark will be reflected on both sides to form "three light marks", so its price is judged to be very high. In terms of color, cream and lemon colors are inferior to honey, while brown and gray are rated lower. Put the cat's eye into the light. It can show a very clear light, and when you turn it, the light bar will shake left and right. This is the discoloration phenomenon of the cat's eye.
In addition to chrysoberyl, there are other types of gemstones that can show a luminous deformation effect like a cat's eye. Like calcium carbide, apatite, blue crystal, etc., there are also minerals [tiger's eye] that produce the same effect due to their asbestos fibrous tissue relationship, but they are incomparable with golden-green cat's eye. There is a yellow-green cat's eye on the crown of the Shah of Iran, weighing 147.7 carats. Pearls can be divided into natural pearls and cultured pearls, and cultured pearls can be divided into seawater pearls and freshwater pearls. Natural pearls are produced in small quantities and are expensive; cultured pearls can be produced in large quantities, so the price is much lower. The main difference between the two is that natural pearls and cultured pearls do not have a nucleus inside. The core of natural pearls is often just some sand or parasites, or even no core. The core of cultured pearls is a larger artificially made round bead, so the outer coating is thinner. On the body surface, natural pearls have a random growth environment, foreign matter in the core rarely rolls, and their appearance is poorly rounded. The core of cultured pearls is rounded, so the roundness is better after the beads are formed. Due to the long growth time of natural pearls, the texture of natural pearls is fine, the bead layer is thick, the skin is smooth, there are few "bubbles", and they are relatively transparent. Cultured pearls have short sounds when they are formed, so the bead layer is thin, the texture is rough, the luster is "waxy", and there are often some uneven "bubbles" on the surface, and the transparency is also poor. If it is a perforated pearl, use a magnifying glass to carefully observe the inside of the hole. If it is a cultured pearl, you can usually see a brown boundary inside the pearl. This is the dividing line between the inserted core and the nacre that grows later.
Imitation pearls often appear on the market. They are usually made of glass beads coated with fish scale powder or silver powder. Their luster is obviously different from real pearls, and their weight is also different. Anyone with a little experience can identify it. . If it is scratched with a fingernail or a knife, the true face of Mount Lu will be revealed immediately. Peridot is a medium-to-low-grade gemstone with a greenish-yellow color similar to olive. The most common peridot imitations on the market are made of colored glass. The main difference between the two is that olivine has an obvious "double shadow", while glass does not; crystalline inclusions are often visible in olivine, and glass only contains bubbles; olivine has a specific gravity of 3.5 and a hardness of 7, which is higher than that of glass. The specific gravity (2.6) and hardness (6) are both large.