Diamonds are polished from diamonds?

Diamond

Diamond, also called diamond, is commonly known as "diamond". The chemical formula is c, which is the same element of carbon as graphite. It is a kind of diamond with excellent physical properties such as super hard, wear-resistant, heat-sensitive, thermal conductive, semiconductor and far-reaching. It is known as the "King of Hardness" and the King of Gemstones. The angle of diamond crystal is 54 degrees 44 Minutes and 8 seconds. Traditionally, people often refer to processed diamonds as diamonds, while unprocessed diamonds are called diamonds. In our country, the name diamond was first found in Buddhist scriptures. Diamond is the hardest substance in nature. The best color is colorless, but there are also special colors, such as blue, purple, golden yellow, etc. Diamonds of these colors are rare and are treasures among diamonds. India is the most famous diamond producing country in history. Many famous diamonds in the world such as "Mountain of Light", "Prince Regent" and "Orlov" are all produced in India. The production of diamonds is very rare, and polished diamonds are usually one billionth of the mined quantity, so they are very expensive. After polishing, diamonds are generally round, rectangular, square, oval, heart-shaped, pear-shaped, marquise-shaped, etc. The heaviest diamond in the world is the "Cullinan" produced in South Africa in 1905, weighing 3106 carats. It has been ground into 9 small diamonds, one of which is called the "Star of Africa" ??Cullinan No. 1. The weight of diamonds still ranks first in the world's famous diamonds.

Use 1: When a person takes diamond powder, the diamond powder will stick to the stomach wall. During long-term friction, it will cause people to get gastric ulcers. If not treated in time, they will die from gastric bleeding. A chronic poison that is hard to be wary of. During the Renaissance, chronic poisons made of diamond powder were popular among Italian wealthy families

Crystal structure:

The unit cell is a face-centered cubic structure, and each unit cell contains 2 Group 8 C atoms.

A simple way to identify diamonds

As society’s demand for jewelry diamonds increases, artificial diamonds and other counterfeit diamonds continue to expand the market, and even some jewelry operators cannot tell the difference. . Here are a few simple ways to identify the authenticity of diamonds.

1. Single refractive index of diamonds

The single refractive index of diamonds is determined by the essential characteristics of diamonds. Most other natural gems or artificial gems are birefringent. When observing the counterfeit diamond under a 10x magnifying glass, from a slightly oblique angle from the front, it is easy to see that the angular lines have overlapping images and show two bottom lights at the same time. For materials with a small difference in birefringence, such as zircon, the image of overlapping background light can also be seen.

2. The adsorption of diamonds

Diamonds have a certain affinity for oil and dirt, that is, oil and dirt are easily adsorbed by diamonds. Therefore, when you touch the diamond with your fingers, it will feel sticky and your fingers will seem to have a sticky feeling. This is something no gemstone has. This method requires training to master the subtle differences.

3. Characteristics of straight lines

The diamond surface is polished very smoothly. Use a pen dipped in ink and scratch it on the diamond. If it is a real diamond, what will be left on the surface is a smooth and continuous line, which is characterized by a straight line. What the counterfeit products leave behind are lines composed of small dots. A magnifying glass should be used for observation with this method.

4. Unique diamond luster

Roughly under 100-degree incandescent light, it is easy to see which diamond has the diamond luster by comparing well-cut diamonds with counterfeit ones. This method should not be performed under too dark or too strong lights.

High-hardness artificial diamond

The Research and Development Center of General Electric Company of the United States has synthesized artificial diamond with an atomic density per unit volume exceeding that of any existing solid object, and its hardness exceeds that of natural diamonds. Diamond is the hardest material in the world. Natural diamond contains ninety-nine percent of the carbon 13 isotope. According to scientists' observations, as the density of carbon-13 isotopes increases, the distance between atoms will slightly shrink, making artificial diamonds harder than natural diamonds with slightly looser atomic arrangements.

In the process of synthesizing artificial diamond, scientists first precipitate the carbon elements in methane gas rich in the carbon 13 isotope into small diamond fragments through a chemical evaporation process, and then use very high pressure to break down these small fragments, and Recrystallizes into massive diamonds weighing up to 3 carats.

Diamonds often appear in colors such as yellow, brown, blue, green and pink, but colorless ones are particularly preferred. Only 10 extra-large gem-grade diamonds weighing more than 620 carats (124 grams) have been discovered in the world. The largest of them is Cullinan, weighing 3106 carats (621.35 grams) and measuring 5 × 6.5 × 10 cm. , discovered in the Premier Rock Pipe in South Africa in 1905. The Chinese Changlin Diamond weighs 158.786 carats. It was discovered in Linshu County, Shandong Province in 1977 and is listed as a world-famous diamond. The world's main diamond producing areas include Australia, Zaire, Botswana, the former Soviet Union, South Africa, Brazil, Namibia, Ghana, Central Africa, Sierra Leone and China.

It is Category 10 on the Mohs Hardness Scale.

Attachment: Giant and large-grain diamonds produced in my country

In the two decades since 1971, several diamonds of more than 50 carats and more than 100 carats have been discovered in my country. , arranged as follows in order of discovery time:

[1] On September 25, 1971, a 52.71-carat diamond was discovered beside the Suqian Highway in Jiangsu Province.

[2] On December 21, 1977, in Changlin Brigade, Linshu County, Shandong Province, female member Wei Zhenfang discovered a high-quality giant diamond weighing 158.786 carats. It was completely transparent, light yellow in color, and could be called a diamond. Diamond’s “Best in China”. Named "Changlin Diamond"

[3] On August 15, 1981, a 124.27-carat giant diamond was discovered in Chenbu, Tancheng, Shandong. It was named "Chenbu No. 1".

[4] In September 1982, a 96.94-carat diamond was discovered in Chenbu, Tancheng, Shandong.

[5] In May 1983, a 92.86-carat diamond was discovered in Chenbu, Tancheng, Shandong.

[6] On November 14, 1983, a 119.01-carat giant diamond was discovered in Mengyin, Shandong, and was named "Mengshan No. 1".

Diamond is polished diamond, also known as diamond, and the mineral name is diamond. The English name Diamond comes from the ancient Greek word Adamant, which means hard and inviolable substance.

① Usually refers to gem-grade diamonds, especially cut-shaped gem-grade diamonds. In fact, there is no such distinction between diamonds and diamonds abroad. The same word "diamond" is used in English, but In China, the word "diamond" is often used in the field of mineralogy, and the word "diamond" is used in the field of gemology. But this is not always the case. For example, although "industrial diamonds" do not belong to the field of gemology, people are accustomed to calling them this way, so they are also used in this entry.

② Gem-quality diamonds are colorless and transparent, but the most common ones are those with a slightly yellowish tint. The darker the yellow or brown tone, the lower the grade. There is a colorless and transparent one with a bit of blue called "water and fire color", but it is a good product. Those with deep blue, deep black, deep golden yellow, red, and green are even rarer treasures, and are called "brilliant diamonds" or "exotic diamonds." Diamonds from the same mining area have similar "pigment" characteristics, so that they have Experienced people can often identify the origin of a diamond based on this. The first invention of the standard round brilliant cut was in 1914 by Tokovsky, a diamond cutter in Antwerp, Belgium. The criteria for identifying diamonds are called the 4Cs, which are clarity, color, cut, and carat weight. Clarity refers to the diamond’s inclusions and should not be called flaws. The presence of inclusions illustrates the naturalness of the diamond. Of course, we still hope that the fewer such inclusions, the better, so there is a clarity classification. Namely: LC, VVS, VS, SI, P level. In the past, people did not know how to polish diamonds and could only use rough diamonds as jewelry. The era when diamond crystals truly became diamonds and turned into jewelry was around 1450.

At that time, diamonds only had 17 sides. The diamond ring worn by the Queen of England who was in power from 1558 to 1603 was just an octahedral diamond crystal with a top ground off as a ring face. It was not until 1919 that a Polish man named Tolkowsky living in the United States designed a 58-turn diamond cutting process, which is still used today. This cutting is accurate based on the refractive index coefficient of the diamond and other factors. The calculated value cannot be changed arbitrarily, otherwise the polished diamond will have no luster or light leakage.

Chemical composition

The chemical composition of diamonds is carbon, which is the only single element among gemstones. Belongs to the equiaxed crystal system. The crystal shapes are mostly octahedron, rhombohedral dodecahedron, tetrahedron and their polymorphs. Pure diamonds are colorless and transparent, showing different colors due to the mixing of trace elements. Strong diamond luster. The refractive index is 2.417 and the dispersion is medium, 0.044. Homogeneous body. Thermal conductivity is 0.35 cal/cm/s/d. Tested with a thermal conductivity meter, the response is the most sensitive. With a hardness of 10, it is the hardest mineral known so far. Its absolute hardness is 1,000 times that of quartz and 150 times that of corundum. It is afraid of heavy blows and will cleave and break after a heavy blow. A set of cleavages is complete. Density 3.52 g/cm3. Diamonds are luminescent and can emit light cyan phosphorescence at night after being illuminated by sunlight. X-ray irradiation emits sky blue fluorescence. The chemical properties of diamond are very stable and are not easily soluble in acids and alkali at room temperature, and acids and alkali will not affect it.

The difference between diamonds and similar gemstones and synthetic diamonds. Common substitutes or fakes in the gem market include colorless gemstones, colorless spinel, cubic zirconia, strontium titanate, yttrium almandine garnet, yttrium gallium garnet, and artificial rutile. Synthetic diamonds were first successfully developed in Japan in 1955, but were not mass produced. Because synthetic diamonds are more expensive than natural diamonds, synthetic diamonds are rare on the market. Diamonds can be distinguished from similar gemstones by their unique hardness, density, dispersion, and refractive index. For example: imitation diamond cubic zirconia is mostly colorless, has strong dispersion (0.060), strong gloss, and high density of 5.8 g/cubic centimeter, and it feels heavy when weighed by the hand. Yttrium almandine has a soft dispersion and is difficult to distinguish from diamonds with the naked eye.

Cause of formation

Modern science and technology and methods provide new ideas and methods for exploring the formation of diamonds. Diamond is the hardest and simplest gemstone in the world. It is a natural crystal composed of carbon and has a cubic structure. Its composition is basically the same as that of our common coal, pencil lead and sugar. Carbon crystallizes to form graphite (black) under higher temperatures and pressures, and in high temperatures, extremely high pressures and reducing environments (usually An oxygen-deficient environment) crystallizes into precious diamonds (white). In order to understand the origin of diamonds, first look at the original rock that contains diamonds.

Since diamonds were discovered in India, we have been hearing stories of people picking up diamonds by rivers and river beaches. This is because the original rock containing diamonds somewhere upstream of the river has been weathered and broken. Later, the diamonds were carried downstream with the water flow, and the heavier diamonds were buried in the gravel. What is the original rock of diamonds? In 1870, diamonds were dug out of the loess on a farm in South Africa. Since then, the excavation of diamonds has moved from the river bed to the loess. Under the loess is the hard dark blue rock, which is the original diamond rock-kimberlite (kimberlite). What is kimberlite? Kimberlite is a kind of alkaline ultrabasic volcanic rock formed deep in the earth and containing a large amount of volatile components such as carbonic acid gas. This rock often contains peridotite and eclogite fragments from the deep earth. The main mineral components include olivine. Stone, phlogopite, carbonate, pyroxene, garnet, etc. Research shows that Kimberley magma was formed 150 kilometers deep in the earth. Because this rock was first discovered in Kimberley, South Africa, it was named after that place.

Another type of original rock containing diamonds is called lamproite. It is a peralkaline magnesia volcanic rock, mainly formed of leucite and volcanic glass, and may contain pyroxene. , olivine and other minerals, typically produced in Argyle, Western Australia.

Scientists have studied diamonds and primary inclusion minerals from different mines around the world and found that the formation conditions for diamonds are generally a pressure of 4.5-6.0Gpa (equivalent to a depth of 150-200km) and a temperature of 1100-1500 degrees Celsius. Although theoretically, diamonds can be formed in various periods/stages of the earth's history, most diamonds currently mined in mines were mainly formed in two periods: 3.3 billion years ago and 1.2-1.7 billion years ago. For example, some diamonds in South Africa are about 4.5 billion years old, indicating that these diamonds began to crystallize deep in the earth shortly after the birth of the earth. Diamonds are the oldest gems in the world. The formation of diamonds requires a long historical process, which can be confirmed by the fact that diamonds are mainly produced in ancient stable continental areas on the earth. In addition, the impact of extraterrestrial bodies on the earth produces instantaneous high temperature and high pressure, which can also form diamonds. For example, in 1988, the Soviet Academy of Sciences reported that diamonds were found in meteorites, but the diamonds formed by this effect have no economic value.

Rare diamonds mainly appear in two types of rocks, one is peridotite and the other is eclogite, but only the former has economic significance. There are two types of diamond-containing peridotite discovered so far: kimberlite (named from a place in South Africa - Kimberley) and lamproite. Both of these rocks are formed by volcanic eruptions. The rocks formed deep in the earth are brought to the surface or shallow parts of the earth by volcanic activities. This kind of magma is mostly produced in the shape of rock tubes, so it is commonly known as "pipe ore" (that is, primary ore). Diamond-containing kimberlite or lamprophyre is exposed on the surface. It is weathered and broken by external forces such as wind and rain. Under the erosion of water, the broken original rock together with diamonds is carried to the river bed or even the coast. The zones are multiplied to form alluvial placer deposits (or secondary deposits).

Famous Diamonds

The 10 largest diamonds in the world

1. "Cullinan". It was discovered in the Premier Mine in South Africa on January 21, 1905. It is pure and transparent with a light blue tint and weighs 3106 carats. It was later processed into 9 large diamonds and 96 smaller diamonds. The largest one is called "Star of Africa I", which is drop-shaped and is set on the scepter of the British King. The second largest one is called "Star of Africa II", square, 64 faces, weighing 317 carats, and is set in the British Empire Crown.

2． Braganza. Discovered in 1725, it is the largest diamond found in Brazil. It is nearly colorless with only a slight yellow tint and weighs 1,680 carats. Later, his whereabouts were unknown. Some people suspect that this diamond may later undergo a more authoritative appraisal and find that it is not a diamond, but a topaz.

3． A large unnamed diamond. In 1919, a gem diamond weighing 1,500 carats was found in the Premier Mine. The color was also similar to Cullinan. Therefore, some people thought that it and Cullinan were broken from the same large crystal, so they did not give this piece of diamond. Diamonds are specifically named.

4. Eureke. In 1893, it was discovered in the Jaggersfontein diamond mine in the Orange Free State, South Africa. It is smooth and transparent, blue-white in color, has excellent luster, and is a high-quality diamond. The largest one weighed 69.68 carats and was called "incomparably noble".

5. Star of Sierra Leone. Sierra Leone’s diamonds are famous for their high quality, large particles and good octahedral crystal shape. The Sierra Star was discovered in the Yangama diamond mine in February 1972. It weighs 968.9 carats and is colorless.

6． Coldman. De Dios. It is the largest diamond discovered in Brazil after the discovery of "Braganza". It weighs 922.5 carats and has an excellent blue-white color.

7. Kohinur is the oldest known diamond in the world. According to legend, it was discovered in Golgotha, a famous ancient diamond mining area in India, as early as the 13th century. The rough stone weighs about 800 carats and is called "Kushnur".

It was later processed into an oval shape, weighing 108.83 carats, colorless (slightly gray), and renamed "Mountain of Light".

8. The Great Mogul is also one of the world's famous ancient diamonds. It was discovered in the Kola mining area in India around 1630-1650. The rough stone weighed 787.5 old carats and was processed into a rose shape. Its whereabouts are unknown.

9. Weyie River is a large diamond discovered in the Weyie Valley placer mine in Sierra Leone in 1945. The original stone weighed 770 carats, was nearly colorless, and was of very high quality. It was later cut and processed into 30 cut diamonds. The largest one is 31.35 carats and is named "Victory Diamond".

10. Golden Jubilee was discovered in the Premier Mine in South Africa in 1986. The original stone weighed 755.50 carats and was dark golden brown. Later, a large diamond of 545.67 carats was polished. This is the largest cut diamond currently available. The diamond is now embedded in the Thai King's scepter.

Other diamonds

Human beings have mined and utilized diamonds for thousands of years, but gem-quality diamonds larger than 20 carats have been quite rare since ancient times. Diamonds larger than 100 carats are considered national treasures. It is said that there are more than 1,900 extra-large diamonds larger than 100 carats found in the world, including 21 diamonds larger than 500 carats and only 2 diamonds larger than 1,000 carats. The largest diamond in the world so far was discovered in Premier, Zaire, South Africa on January 27, 1905. The diamond was named "Cullinan" and weighed 3,106 carats. 100mm long, 65mm wide, 50mm thick. Gem industry experts estimate the value of Cullinan to be as high as $7.5 billion. In 1907, the Transvaal local government of South Africa presented this giant diamond to King Edward VII of England. The King of England handed over the processing of this giant diamond to the famous Dutch Ascher Company, which had processed large diamonds such as the "Incomparable Noble". After taking over the project, the company studied the giant diamond for several months. On February 10, 1908, the giant diamond was split into several large pieces and processed into 9 large diamonds and 98 small diamonds. One piece was deliberately left behind ( Weighing 9.5 carats) rough stone. The total amount of polished diamonds processed was 1,063.65 carats. The largest diamond processed was named "Cullinan No. 1", also known as the Star of Africa, weighing 530.02 carats and is a pear-shaped faceted diamond. "Cullinan II" is a cut-angle baguette diamond weighing 317.4 carats. "Cullinan III" is a pear-shaped diamond, weighing 95 carats, "Cullinan IV" is a square diamond, weighing 64 carats, there is also a heart-shaped diamond weighing 19 carats, and two marquise diamonds, each weighing l1 .5 carats and 8.8 carats. The last two are baguette diamonds (weighing 6.8 carats) and rugby-shaped diamonds (weighing 4 carats). Four of the diamonds are set on the British crown. This crown is now collected in London. Among the royal treasury at Wakefield Tower.

At the beginning of the 17th century, a 309-carat rough diamond was picked up from a diamond placer mine in Golconda, India, and was later named the Orlov diamond. At that time, according to Shah Jehan's order, a well-known diamond processing expert planned to process it into the shape of an "Indian rose", but he failed to fully achieve his wish and lost a lot of weight (only 189.62 carats were ground out). According to legend, this wonderful, rare and flawless diamond was later used as the eyeball of a statue in the Salinga Temple in India. After Delhi was captured by the Persian king Najir in 1739, the diamond was decorated on Najir's throne and named "Jer Aonur". The diamond was later stolen and fell into the hands of an Armenian. In 1767, he deposited the diamond in a bank in Amsterdam. In 1772, he sold the diamond to Ivan, the royal jeweler. Ivan bought it to Count Orlov in 1773 for 400,000 rubles. In the same year, Orlov dedicated the diamond to Catherine II as a gift for her name day, and then it was welded into an carved sterling silver base and set on the top of the Russian scepter. The Orlov diamond is clean and very rare. It has a slight light blue-green color and several very small light yellow inclusions in the crystal.

The diamond is 22mm thick, 31--32mm wide, and 35mm long. This diamond is currently stored in the former Soviet Union Diamond Foundation. Another famous diamond, the Shah, was presented to the Tsarist government by Mirza, the Prince of Persia, in 1829, with the intention of repairing the relationship that had deteriorated due to the murder of the Russian envoy in Persia. country relations. The "Shah" diamond weighs 88.7 carats, is light yellowish brown, and is flawless except for a few small cracks deep in the crystal. There are inscriptions in Persian script on the three polished surfaces, which means "Burhan-Nizam-Shah II, 1000 (1591 AD)". After central India came under the occupation of the great Mughals, the diamond fell into their hands. The second inscription means "Jehhan-Shah, son of Jehan-Gir-Shah, 1051 (1641 AD)". The third paragraph of chrome text means "The ruler Qadzhar-Fakht-Ali-Shah Sultan, 1242. (King of Persia, 1842). The diamond was possessed by Najir Shah, approx. It was during the occupation of the Great Mogul in 1739. No one knows where this diamond was found. It is inferred that it may have been found in the Golconda sand mines. It can be engraved on the extremely hard "Shah" diamond. The inscription shows that the skills of Persian artists at that time were unimaginable. Shah-Jehan, the consul of the Great Mughal Empire mentioned in the inscription, was in power from 1627 to 1666, and was later replaced by his son Jeb. He spent the rest of his life in prison. Shahzhe had a great gem addiction. He owned a special workshop and even went there himself to sort and polish gems. His son Jeb not only usurped the throne, but also seized his father's treasures. In 1665, a famous traveler made a fascinating description of the throne of the Great Mogul. The throne was decorated with a large number of gems. On one side of the throne, an 80- to 90-carat diamond hung on the canopy. , surrounded by many emeralds and rubies. This may be the "Shah", which hangs between the Great Mughal and the Jin Dynasty as a protective treasure. There is also a very beautiful diamond called the "Sansi" diamond. , weighing 55 carats, it is said that this diamond was once set on the helmet of the warrior Carl, and was later lost in a fight.

In 1589, the "Sancy" diamond appeared in the treasure house of King Anton of Portugal. It was sold to the lord de Sancy of France for 100,000 old francs. The "Sancy" diamond has been an heirloom of his family for a long time and was later given to King Genglihe II of France and included in the French National Treasures. According to the list, the diamond was looted in 1792. In 1830, Demidov, a descendant of a Ukrainian factory owner, bought it for 500,000 francs. The French government filed a lawsuit over the matter. Five years later, the diamond was awarded to Demidov. The 410-carat "Prince Regent" diamond also has a touching story. Legend has it that it was picked up by an Indian slave in the mine of the famous Golconda mine in 1701. He wanted to With this diamond, he changed his life and gained freedom, so he hit the thigh with a T-shaped pick while no one was paying attention, causing blood to flow. The Indian endured great pain and hid the diamond deep in the wound, and used leaves as a bandage to cover the wound. After wrapping it up, he found a British seagoing sailor and was ready to exchange for his freedom. After the sailor saw the huge diamond, he wanted to get it immediately and was prepared to risk everything. The sailor and the slave quickly reached an agreement. The sailor kept it secret from the captain. The Indians were hidden in the jute in the cabin. When the ship sailed into the high seas, the sailors gave the slaves food at night, killed the slaves with daggers while they were eating, and threw the victims into the sea. The ship docked in Madeira. After that, the sailor sold the diamond to the British governor of the city, Sir Peter. After the sailor got the money, he quickly squandered it. In the end, he was so ashamed that he hanged himself in 1717 for 3.4 million. The Golden Franc sold the diamond to the French Regent, the Duke Orleonsky. The Duke ordered the diamond to be processed, and thus the diamond "Prince Regent" was born. The birth of this diamond was difficult, and it took two full days to polish it. Years later, the processed weight was 140.5 carats. When Liudovic XIV was crowned in 1722, the diamond was set in his crown. In 1792, at the beginning of the French Revolution, it was lost along with other symbols of royal power and moved to Berlin. . It was later sold to Napoleon by a German jeweler.

In the 1790s, it was used as collateral by Napoleon to secure his expedition. When Hitler captured Paris in 1940, the diamond was hidden in the wainscoting of the marble fireplace in Chambord. The diamond is currently on display in the Louvre. The diamond grain size is 30 X 29 X 19mm. The diamond is a brilliant cut shape, exquisite workmanship, and has different effects of luster and "fire". In 1762, the talented palace jeweler Borgier made the large crown for Catherine II's coronation ceremony and won praise for its richness and exquisiteness. He created a new world of brilliant diamond cuts, and the crown always had *** Inlaid with 4936 diamonds weighing 2858 carats, the entire crown weighs 1907 grams. The "spinel" diamond decorating the crown weighs 398.72 carats and is listed as one of the seven historical diamonds of the former Soviet Union.

The oldest diamond in the world - the Mago Diamond

The Mago Diamond weighs 787.50 carats and is the earliest giant rough diamond discovered in history. It was discovered in India in 1304. Gorkon region. This area is also the place where diamond deposits were first discovered in the world. To date, its weight ranks fourth among rough diamonds. The crystal shape of this rough stone is incomplete, but it is colorless, transparent, and radiant, making it extremely precious. The rough stone went through many twists and turns, was stolen many times, and finally fell into the hands of Queen Victoria of England. It was then carefully designed and cut into several pieces of diamonds. Among them, there are two most famous ones. One is named Kon-i-noor, weighs 108.93 carats, is oval in shape, and is set in the crown of the Queen Mother of the United Kingdom; the other is named Orlov ( Orloff), weighs 189.60 carats, is rose-shaped, and is now collected in the Kremlin in Moscow. The weight of the Orloff diamond ranks ninth among polished diamonds.