catalogue
Introduction to hunger
mass unit
chemical composition
Formation principle
Division of Origin World Diamond Resources and Origin
Diamond producing country
The country that produces the best diamonds
Changes in the origin of diamonds
The first diamond mine in the world
Diamond mines in South Africa
The largest single diamond producing area
Diamond resources and producing areas in China.
Evaluation and color selection (color)
Clarity (clarity)
Carat weight
Cut (cut)
Differential hardness test
Thermal conductivity test
Observe reflected light
Look at the growing point
Similar chemical composition test
Imitation of artificial zirconia
Evaluation agency IGI certification
GIA certification
Human resource development certification
other
Crystallization habits of natural diamonds and synthetic diamonds
colour
Surface and internal texture
Enlarge observation
Visible light absorption spectrum
Ultraviolet fluorescence
Cathodoluminescence instrument
Infrared spectrum
electrical conductivity
other
False diamond glass
synthetic spinel
Crystal and topaz
Artificial sapphire
zircon
Lithium niobate
Strontium titanate
Yttrium aluminum garnet (YAG)
cubic zirconia
moissanite
Pay attention to your health
The misunderstanding of diamonds is to buy diamonds to preserve their value.
The brilliance of a diamond comes from its chromaticity.
When buying diamonds, you must buy ones with high purity.
Diamonds with I chroma are the most beautiful.
Radiation from diamonds?
Cutting and segmentation
saw cutting
Forming/shaping
Beating and polishing
Diamonds and love
The reason for the high price is the inherent charm and quality of diamonds.
Diamond culture has a long history.
The exploration of diamond deposits is difficult and expensive.
Mining is huge in scale and extremely difficult.
The diamond processing procedure is complicated and the working time is long.
In the hands of consumers, a diamond has many experiences.
The most expensive diamond in the world appeared in the auction house.
The biggest diamond in history, Clarion diamond.
The most precious 10 diamond in the world, the star of Africa.
Guangzhishan diamond
tirelessly seek improvement
great mogul diamond
Eye of Idol Diamond
Regent diamond
diamond
Blue hope diamond
Xianxi diamond
Taylor Burton diamond
The world's largest 10 diamond Cullinan.
Bragasa diamond
A big unnamed diamond.
European coordinating agency for research
Star of Sierra Leone
Coleman de Dios
Ke chinour diamond
Big mughal
Woyihe diamond
Gold commemorative coin
The historical origin of "fire drill" comes from "fire water"
Transfer from India to the Netherlands
The world's number one diamond "Cullinan"
What does the "drill" of this stone mean?
Diamond Hook "Lan Xue"
Introduction to hunger
mass unit
chemical composition
Formation principle
Division of Origin World Diamond Resources and Origin
Diamond producing country
The country that produces the best diamonds
Changes in the origin of diamonds
The first diamond mine in the world
Diamond mines in South Africa
The largest single diamond producing area
Diamond resources and producing areas in China.
Evaluation and color selection (color)
Clarity (clarity)
Carat weight
Cut (cut)
Differential hardness test
Thermal conductivity test
Observe reflected light
Look at the growing point
Similar chemical composition test
Imitation of artificial zirconia
Evaluation agency IGI certification
GIA certification
Human resource development certification
other
Natural diamonds and synthetic diamonds
Crystallization habit, color surface and internal texture, magnification observation, visible light absorption spectrum, ultraviolet fluorescent cathode luminescence instrument, infrared spectral conductivity, other fake diamonds.
Glass Artificial Spinel Crystal and Topaz Artificial Sapphire Zircon Lithium Niobate Strontium Titanate Yttrium Aluminum Garnet (YAG) Cubic Zirconia Mosanite Misunderstandings about Diamond Maintenance
In order to preserve the value of diamonds, the brilliance of diamonds comes from their chromaticity. If you buy diamonds, you must buy the radiation of the most beautiful diamonds with high purity and chroma. incision
The reason why love is expensive is to cut and saw petals and polish diamonds.
The inherent charm and quality of diamonds have a long history. The exploration of diamond deposits is difficult, and the scale of expensive mining is huge and extremely difficult. The processing procedure of diamonds is complex, and the amount of working hours in the hands of consumers is large. A diamond has gone through many experiences. The most expensive diamond in the world appeared in the auction house. The largest diamond in history, Colijn, drilled 10 diamonds in the world.
African Star, Mountain of Light, AXA Shaxiu, Eye of great mogul diamond Statue, Regent, orlov, Blue Hope, Xianxi, Taylor Burton, the world's largest 10 diamond.
An unknown big diamond in Kurinan Braganza, the star of Eureka Sierra Leone, Coleman de Dios Kuchinour, and the historical origin of the gold commemorative coin of the Great Mughal River.
The "fire diamond" came out of the "fire water" and moved from India to the world's first diamond "Cullinan" in the Netherlands. Because of its meaning, this stone is associated with "Lan Xue".
diamond
1. The name of this mineral is "Diamond", and its English name is Diamond. It comes from agonist in ancient Greece, which means hard and inviolable substance and is recognized as the king of gems. The chemical composition of diamonds is 99.98% carbon. In other words, diamond is actually a kind of carbon crystal with quite high density. 2. Mohs hardness of diamond: 10, which is the highest among natural minerals. Its brittleness is also quite high, and it will still break when it is hit hard. 3. Diamond cutting is the process of cutting diamonds into different shapes according to the shape of their original stones. Among them, eight popular shapes are round, oval, olive pointed, heart-shaped, pear-shaped, square, triangle and emerald. A round drill is the most common shape. 4. Diamonds are natural minerals. The main producing areas of diamonds are Australia, Botswana, Canada, Zimbabwe, Namibia, South Africa, Brazil and Siberia. At present, the main diamond cutting and grinding centers in the world are Antwerp, Tel Aviv, new york, Mumbai, Thailand and Bangkok. Antwerp has the reputation of "the diamond capital of the world", where about half of the world's diamond transactions are completed. "Antwerp Cutting" is synonymous with perfect cut. Diamonds (19) 5. Re-inspection is required to buy diamonds (the certificates of IGI and GIA can be verified directly in official website, and re-inspection is not required) 6. Refractive index: 2.4 17 7. Deviation value: 0.044 (high) 8. Total internal reflection: critical angle: 24.5.
Edit the mass unit of this paragraph.
Card, or translated as carat, carat, is the quality unit of diamond. One card is 200mg. According to legend, in the early days, the diamond was weighed by the fruit of carob tree, and one such fruit weighed about 200mg. Because the density of diamonds is basically the same, the heavier the diamond, the bigger the volume. The bigger the diamond, the rarer it is, and the higher the value of each card.
Edit the chemical composition of this paragraph.
The chemical composition of diamond is carbon, which is the only single element in gem and belongs to equiaxed crystal system. It often contains 0.05%-0.2% impurity elements, of which N and B are the most important, and their existence is related to the types and properties of diamonds. The crystal forms are mostly octahedron, rhombic dodecahedron, tetrahedron and their aggregates. Pure diamond is colorless and transparent, showing different colors due to the mixing of trace elements. Strong diamond luster. The refractive index is 2.4 17 and the dispersion is moderate, which is 0.044. An isotropic object. The thermal conductivity is 0.35 calories/cm/sec/degree. Tested by thermal conductivity meter, the response is the most sensitive. The hardness is 10, which is the hardest mineral known at present. The absolute hardness is 1000 times that of the time, and 150 times that of corundum. It is afraid of heavy blows, and it will be broken by cleavage after heavy blows. A set of cleavage is completed. The density is 3.52g/cm3. Diamonds are luminous, and after being irradiated by sunlight, they can emit light blue phosphorescence at night. X-ray irradiation emits sky blue fluorescence. The chemical properties of diamond are very stable, and it is not easy to dissolve in acid and alkali at room temperature, and acid and alkali will not affect it. The difference between diamonds and similar precious stones and synthetic diamonds. Common substitutes or counterfeits in gem market include colorless gemstones, colorless spinel, cubic zirconia, strontium titanate, yttrium aluminum garnet, yttrium gallium garnet, artificial rutile and so on. Synthetic diamonds were first developed by Japan in 1955, but they were not mass-produced. Synthetic diamonds are rare in the market because they are more expensive than natural diamonds. Diamonds can be distinguished from similar gems by their unique hardness, density, dispersion and refractive index. For example, diamond-like cubic zirconia is colorless, with strong dispersibility (0.060), strong luster and high density of 5.8 g/cm3, which has obvious sense of gravity. Yttrium aluminum garnet has a soft dispersity, so it is difficult to distinguish it from diamonds with naked eyes. It has become a popular gem that people can own and wear. Diamond culture has a long history, and today people regard it more as a symbol of love and loyalty.
Principles of editing this paragraph
Some people say that diamonds are diamonds, but this statement is completely wrong (their difference is equivalent to the relationship between wood and furniture). Diamonds are just products of diamond processing. Modern science, technology and means provide new ideas and methods for exploring the formation of diamond. Diamonds are the hardest and simplest gems in the world. It is a cubic natural crystal composed of carbon. Its treasure map diamonds
The ingredients are basically the same as those of our common coal, pencil lead and sugar. Carbon element crystallizes into graphite (black) at high temperature and high pressure, while it crystallizes into precious diamond (white) at high temperature, extremely high pressure and reducing environment (usually anoxic environment). In order to understand the origin of diamonds, first look at the original rocks containing diamonds. Since the discovery of diamonds in India, we have been hearing stories about people finding diamonds on rivers and beaches. This is because the original rock containing diamonds located in the upper reaches of the river is weathered and broken, and the diamonds are taken downstream with the water flow, and the heavier diamonds are buried in the gravel. What is the original stone of a diamond? 1870, diamonds were dug up in the loess of a farm in South Africa. After that, the excavation of diamonds moved from the river bed to the loess. Below the loess is a hard dark blue rock, which is the original stone of diamonds-kimberlite. What is kimberlite? Kimberlite is an alkaline ultrabasic volcanic rock, which is formed in the deep part of the earth and contains a lot of volatile components such as carbonic acid gas. This kind of rocks often contain peridotite and eclogite fragments from the deep earth, and the main mineral components are olivine, phlogopite, carbonate, pyroxene and garnet. The study shows that kimberlite magma was formed in the deep part of the earth below 150 km. Because this rock was first discovered in Kimberly, South Africa, it was named after this place name. Another kind of original rock containing diamonds is called K-Mg lamprophyre, which is an overbased magnesian volcanic rock. It is mainly formed by leucite and volcanic glass, and may contain minerals such as pyroxene and olivine. Its typical origin is argyle, Western Australia. Through the study of diamonds and their primary inclusion minerals from different mines in the world, scientists found that the formation conditions of diamonds are generally 4.5-6.0Gpa (equivalent to 150-200km depth) and1100-1500℃. Although diamonds can be formed in various periods/stages of the earth's history in theory, most of the mines currently mined were mainly formed in two periods: 3.3 billion years ago and12-1700 million years ago. For example, some diamonds in South Africa are about 4.5 billion years old, indicating that these diamonds began to crystallize in the deep part of the earth shortly after its birth. Diamonds are the oldest gems in the world. The formation of diamonds needs a long historical process, which comes from the fact that diamonds on the earth are mainly produced in ancient times.
The old stable mainland area can be confirmed. In addition, the impact of extraterrestrial stars on the earth can produce instantaneous high temperature and high pressure, and can also form diamonds. For example, the report of the former Soviet Academy of Sciences 1988 found diamonds in meteorites, but the diamonds formed by this action have no economic value. Rare diamonds are mainly produced in two kinds of rocks, one is peridotite and the other is eclogite, but only the former has economic significance. So far, there are two kinds of peridotite containing diamond: kimberlite (named after a place name in South Africa-kimberlite) and K-Mg lamprophyre. Both kinds of rocks are produced by volcanic eruption. Rocks formed in the deep part of the earth are brought to the surface or the shallow part of the earth by volcanic activity. This magma is mostly produced in the form of rock tubes, so it is commonly called "tube ore" (primary ore). Kimberlite or kimberlite containing diamond is exposed to the surface and weathered and broken by external forces such as wind and rain. Under the scouring of water, the broken protoliths and diamonds are taken to the riverbed and even the coastal zone for reproduction, forming alluvial sand deposits (or secondary deposits).
Edit the source section of this paragraph.
World diamond resources and producing areas
General situation of world diamond reserves and production: At present, the proven natural diamond reserves are about 2.5 billion carats, including 650 million carats in Australia and 550 million carats in Zaire. According to the current mining level, the existing diamond reserves can only be mined for 25 years, but with the improvement of prospecting technology, new mining areas are discovered every year, and the diamond reserves in Canada have increased greatly in recent years. Since diamond mining, * * * has mined about 350 tons of diamonds, that is, 65.438+75 billion carats. At present, the annual diamond mining in the world is between 90 million and 654.38+0. Distribution map of world diamond resources.
1 100 million carats, of which the gem grade accounts for 17%-20%. The value of 20% gem-grade diamonds is five times that of 80% industrial diamonds.
Diamond producing country
Diamonds are produced all over the world, and more than 30 countries have diamond resources with an annual output of about 1 100 million carats. The five countries with the highest output are Australia, Zaire, Botswana, Russia and South Africa. The diamond production of these five countries accounts for about 90% of the world's diamond production. Other diamond producing countries include Congo (DRC), Brazil, Guyana, Venezuela, Angola, Central Africa, Ghana, Guinea, C? te d 'Ivoire, Liberia, Namibia, Sierra Leone, Tanzania, Zimbabwe, Indonesia, India, China and Canada. The proven reserves and output of diamonds in China rank around 10 in the world, with an annual output of 200,000 carats. Diamonds are mainly produced in Wafangdian, Liaoning, Mengyin, Shandong and Yuanjiang, Hunan, among which Wafangdian, Liaoning is currently the largest diamond mine in Asia.
The country that produces the best diamonds
As far as the ratio of rough diamonds to gem-grade diamonds is concerned, the best diamonds come from diamonds mined in alluvial deposits in Namibia. These diamonds were naturally weathered and transported to the seaside 1000 miles. After this journey, the fragile part of the diamond was separated. In a specific sedimentary environment, diamonds are regularly distributed in rock layers according to different particle sizes and shapes. The highest gem-grade diamond quartz clock in this mining area is 97%. It is difficult to distinguish which country and which mining area cut and polished the diamond ring surface. Diamonds produced in any mining area are good, medium and poor. Comparing the best diamonds in the mining area with the worst diamonds produced in Namibia, the diamonds in alluvial deposits in Namibia are not necessarily good.
Changes in the origin of diamonds
India was the first country in the world to find diamonds. 3000 years ago, India was the only place where diamonds were produced. From 2500 years ago to the beginning of18th century, the Krishna River, Penna River and their tributaries in India were the only places in the world where diamonds were produced. Many famous diamonds in history, such as kohi-noor, orloff and great mogul, are from India, but at present, the diamond production in India is very small. By 1725, the discovery and mining of Brazilian diamonds made Brazil replace India and become the most important diamond producing area in the world. After 1867, alluvial sand deposits and a large number of primary kimberlite cones were discovered in South Africa, making South Africa the most important diamond producer in the world, and its output has been in the forefront of the world for a long time, thus creating a new era of diamond industry. 1905, the world's largest kimberlite cone-Primir cone was discovered in Jalia, South Africa, where the largest diamond (Cullinan diamond) was found. At present, South Africa has the largest and most modern Venice diamond mine in the world. South Africa's diamonds are large in size and high in quality. 50% of diamonds are machinable. Although the output is not as good as that of Australia and other countries, the output value has always been in the forefront of the world. From 1979, where diamonds were found in K-Mg porphyry in Western Australia, to 1986, Australia's diamond production is dominant, but the gem grade only accounts for 5% of its production. Australian diamonds are mainly distributed in Bingala and Copton, New South Wales, Western Australia, especially the argle deposit, with a reserve of 550 million carats. Botswana is rich in high-quality diamonds, with gem grade accounting for 50% and the output value ranking first in the world. Botswana's diamonds come from kimberlite mined in the open pit. Huge mines include Olapa rock pipe (1967), Letihakkena rock pipe (1977) and Jiwaneng drilling mine (1982). The total output of the three mines exceeded 1500 in 1989. Russian diamonds are mainly distributed in Yakutia region in central Siberia, where more than 100 kimberlite cones containing diamonds have been found. 1988, Russia discovered a new diamond mine near Europe. At present, Russia's diamond production is about 6.5438+0.2 million carats, half of which are gem-grade. Over the years, Russia has formed an independent diamond mining, processing and sales system, with a large number of diamonds, excellent quality and good uniformity, which is highly competitive in the market. A few years ago, it was reported that a large number of kimberlites were discovered in northern Canada. In a few years, diamond production may account for 10% of world production.
The first diamond mine in the world
1871July 16, the cooperative mining team in Fort Koulis was successful. They dug deep in the land covering tens of square meters and finally found the diamond they dreamed of on this day. The world's first diamond mine was born. The name "Koulis Fort Mine" is also called "New Thermal Wave Mine".
Diamond mines in South Africa
When it comes to diamonds, people living there think of South Africa. Adamantane produced in South Africa is famous for its large particles and good quality. 50% of the rough diamond quartz clock mined from the mine can reach the gem level. More than 50 years ago, South Africa's diamond output ranked first in the world, so customers often asked, "Is this South Africa's diamond?" With the passage of time, South Africa's diamond production has decreased year by year. 1987, South Africa's diamond output was 100000 carats, accounting for about 10% of the world's total output.
The largest single diamond producing area
1905, a giant diamond weighing 3 106 carats was found in the Primir mine in South Africa, and it was named "Cullinan". In 19 1500 carats, another diamond weighing 1500 carats was found in this mine. According to its shape, color and repeated comparative study, it is determined that it should be the same as Cullinan. 1980 the third large diamond weighing 599 carats was found in this mining area. Primir mine in South Africa is recognized as the origin of giant diamonds in the world.
Diamond resources and producing areas in China.
The proven reserves and output of diamonds in China rank around 10 in the world, with an annual output of 200,000 carats. Diamonds are mainly produced in Wafangdian, Liaoning, Mengyin, Shandong and Yuanjiang, Hunan, among which Wafangdian, Liaoning is currently the largest diamond mine in Asia. China discovered kimberlite and diamond primary deposits in Guizhou and Shandong in 1965. 197 1 A primary diamond deposit was discovered in Wafangdian, Liaoning Province. Two primary diamond deposits that are still being mined are located in Wafangdian, Liaoning Province and Mengyin, Shandong Province. Diamond placers are found in Yuanjiang river basin in Hunan, Tibet and Guangxi and Tancheng-Lujiang fault across Jiangsu and Anhui provinces. At present, there are three major diamond producing areas in China: Wafangdian, Liaoning, Mengyin-Linshu, Shandong and Yuanjiang, Hunan. All of them are kimberlite type, but no primary ore has been found in Hunan. Among them, Liaoning has better quality and Shandong is bigger. At present, the largest diamond found in China is Chang Lin diamond, which was found in Shandong on June1977+February 2 1. Chang Lin diamond weighs 158.786 carats and is octahedral, with clean, transparent and light yellow texture. It is also said that the largest diamond in China is Jinji diamond, which was also found in this area, weighing 28 1.25 carats, but it was plundered by the Japanese army during World War II, and its whereabouts are still unknown.
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Consider (4C) from the following four aspects:
Color (color)
Colorless is the best, and the darker the tone, the worse the quality. In the classification of colorless diamonds, the top color is D color, which is arranged down to Z in turn. Here, only the color scales from D to J are mentioned. D-F is a colorless color scale, and G-J is close to a colorless color scale. Starting from K, there is basically no collection significance, and the ring holders below K color are also very beautiful. Because diamonds will gradually turn yellow from K, when choosing diamonds, choose the color above H. I-J grade also belongs to the category of near colorless, but a trace of yellowish diamonds with yellow, green, blue, brown, pink, orange, red, black and purple are precious and expensive among diamonds. Red diamonds are the most precious. Different countries and regions adopt different color grading systems. American Gemological Institute is divided into 23 grades, which are represented by English letters D-Z respectively. The most commonly used one is 1 1 level d-n. The color grading system in Europe is represented by CIBJO. The new national standard of China 1996 integrates GIA and CIBJO. The standard divides colors into 12 grades, which are expressed by D-N and < n, and also adopts percentage method and text description. Diamond color grade D 100 extremely white E 99 F 98 excellent white G 97 H 96 white I 95 yellow white (brownish gray) J 94 K 93 light yellow (brownish gray) white L 92 M 9 1 light yellow (brownish gray) N 90.
Clarity (clarity)
Diamond gold commemorative coin
Clarity classification is based on the position, size and quantity of inclusions. From high to low, it can be divided into FL, IF, VVS 1, VVS 2, VS 1, VS 2, Si 1, Si2, Si3, P 1, P2, P3. Observe the diamond carefully under a ten-fold microscope. Among them, FL-"Perfect" is perfect. If there is no flaw inside and outside-under the magnifying glass of ten times, there is no flaw inside. Under the magnifying glass of ten times, there are only slight flower marks on the surface, vvs 1, vvs2-"very, very fine", very, very small. There are defects that are difficult to see under a magnifying glass of ten times. The definition of VVS 1 is higher than that of VVS2. VS 1 and vs 2-"very thin", very small. Defects can be seen under a magnifying glass of ten times, but it is difficult for the naked eye to recognize them. The definition of VS 1 is higher than that of VS2. Si 1 and si2- "slight inclusions", small flaws, which may be visible to the naked eye. I 1, I2, i3-"Imperfect" is flawed and visible to the naked eye.
Carat weight
Under the same conditions of the other three C's, the price of a diamond is directly proportional to the square of its weight, and the greater the weight, the higher its value. The weight of diamonds is measured in carats. 1 carat (carat) = 0.2g (gram). Divide one carat into 100 parts, with one point for each part. The price tag in the mall says 0.3ct, and 0.4ct stands for 30 minutes and 40 minutes. The weight is also graded, 0.30ct-0.39ct, 0.40ct-0.49ct, 0.50ct-0.69ct, 0.70-0.89ct, 0.90-. 1.50-2.00ct (each level is separated by commas, not the first level. Even if it is one point short, the price will be much different, which is why it is difficult to buy such things as 0.48~0.49, 0.68~0.69, 0.88~0.89 ...).
Cut (cut)
D grade diamond
A rough diamond will not be noticed even if it is thrown on the road. It is cutting that gives it a second life and gives it a gorgeous fire color. Cutting refers to the geometric shape and arrangement of various valve faces of finished bare diamonds. Cutting is divided into three categories: cutting ratio, polishing and decoration. Each project has five grades, from high to low, excellent, very good, good, average and poor. Generally, it is a standard round drill cutting. Top-cut stone can achieve the perfect proportion closest to light reflection, that is, three EX (excellent) cutting, but the price of this kind of cutting is a little expensive, because its yield is relatively low, which is about 5% higher than that of three EX cutting. But the Shi Huo color of the three EXs is absolutely the most beautiful. Several common cutting forms-round emerald, oval pear, princess square, pillow core and eight arrows-the price calculation formula of Cupid cut diamond is: the weight, color (vertical bar) and clarity (horizontal bar) of the diamond, and the unit price is × 100× RMB exchange rate (6.9), that is, Africa Star I.
You can get the price of diamonds. For example, if you calculate the price of 52 cents (0.52 carats) F VVS 1, you can find that the unit price of this grade of diamonds is $5,400, so the price is calculated as: 54× 100×6.9 (RMB exchange rate )× 0.52 (diamond carats) = 19375.20.