Alchemy alchemy
/kloc-in the 0/8th century, platinum began to enter Europe, and soon it became an extremely important part of alchemy fanaticism. Because of its special chemical properties, platinum became an essential ingredient in medicine when fearless inventors tried to convert lead into gold.
kings of metal
175 1 year-Shortly after Teffer Schiffer, a Swedish scientist, classified it as a precious metal, platinum became the royal family's favorite. 65438+In 1980s, French King Louis XVI announced that it was the only metal suitable for the king, and his jeweler Marc Etienne Giannetti designed several platinum products for him, including a gorgeous sugar bowl.
Platinum and its characteristics
Mineralogical characteristics of natural platinum
Platinum group elements include platinum, palladium, rhodium, ruthenium, iridium and osmium. In nature, they often occur together, and together with gold and silver, they are called precious metal elements.
In mineral classification, platinum group minerals belong to natural platinum subgroup, including natural elemental minerals such as iridium, rhodium, palladium and platinum. Platinum group minerals are all equiaxed, with few single crystals and occasionally cubic or octahedral fine crystals. Generally, it is an irregular granular, dendritic, grape-like or massive aggregate. The color and stripes are silvery white to steel gray; Metallic luster, opaque. Simple principle platinum has no solution, serrated fracture and ductility. It is a good conductor of electricity and heat.
The natural element platinum is a rare precious metal element in the earth's crust, and its symbol is Pt. The mineral name of natural platinum is natural platinum. It is a simple mineral of natural element platinum, and its chemical formula is Pt. The specific gravity of natural platinum is15.5 ~ 21.5; The refractive index is 56.5 ~ 60.0.
[Edit this paragraph] Platinum deposit types and platinum reserves
Platinum deposit type
Platinum ore refers to the general name of platinum group metal minerals. It has many types of deposits.
1, China platinum mine
In China, platinum group metals are mainly produced in copper-nickel sulfide deposits. Among them, it is mainly produced in Jinchuan copper-nickel sulfide deposit. More than 20 kinds of platinum group metal minerals have been found in Yunnan platinum mine in China. Among them, there are mainly arsenic platinum ore, tellurium platinum ore, bismuth tellurium platinum ore, bismuth tellurium palladium ore, yellow bismuth tellurium palladium ore, iron platinum ore, sulfur platinum ore and so on. The main body of Yunnan platinum deposit with industrial value belongs to the type of poor copper, nickel, platinum and palladium deposit caused by molten hydrothermal solution in the late magmatic period. 1983, the largest jinbaoshan platinum mine in China at that time, was also one of the platinum mines with industrial value.
2. World Platinum Deposits
Platinum group metals are mainly produced in copper-nickel sulfide deposits related to mafic-ultramafic rocks (basic-ultrabasic rocks). In recent years, some new types of platinum-containing deposits have been discovered in the world. For example: black shale copper deposits containing platinum, platinum deposits in various copper-gold veins, porphyry copper-molybdenum deposits containing platinum group metals, pyrite copper deposits containing platinum, cassiterite-sulfide deposits containing platinum, uranium-sulfide deposits containing platinum and many other types.
The most famous platinum group metal deposit in the world is the copper-nickel sulfide platinum-bearing deposit in Bushveld layered complex in South Africa. Mineralization of platinum group metals is concentrated in Meilin base. South Africa is one of the three largest platinum producers in the world.
[Edit this paragraph] Platinum reserves and production
In nature, platinum is not as abundant as gold. According to incomplete statistics, the total reserves of platinum group mineral resources in the world are about 3 1 10,000 tons. Among them, the total platinum reserves are about 6.5438+0.4 million tons. Although more than 60 countries have discovered and mined platinum ore, its reserves are highly concentrated in South Africa and the former Soviet Union. Among them, the South African (azania) platinum reserves are about 65438+200,000 tons, of which Transvaal platinum mine is the most famous and the largest platinum mine in the world. The reserves of platinum in the former Soviet Union were 1.866 tons. Natural platinum weighing 8-9 kilograms was found in the platinum mine of Ural placer, and natural platinum weighing 427.5 grams was also obtained in the primary mine. Their total reserves account for 98% of the world's total reserves.
The annual output of platinum in the world is only 85 tons, far less than that of gold. Only a few countries in the world produce platinum. South Africa's platinum production accounts for more than 80% of the global total production; Most of the rest are made in Russia. The annual output of platinum in the world is only 5% of that of gold.
Application and value of platinum
Platinum has excellent properties and is widely used. In the jewelry industry, it is mainly used as decorations and handicrafts. In the chemical industry, it is used to manufacture advanced chemical containers, platinum crucibles, electrodes and catalysts for accelerating chemical reactions. Platinum-iridium alloy is the material for making fountain pen nib.
Discovery and Preliminary Application of Platinum
People's understanding and utilization of platinum is far behind that of gold, with a history of only about 2000 years. Archaeological data show that in more than 700 BC, the ancient Egyptians were able to process platinum into platinum ornaments with high technical level. Long before Columbus discovered the New World, white gold ornaments were also popular among Indians in Central America. However, people in other areas know nothing about platinum. Until the beginning of16th century, the Spanish colonial empire was gradually formed, and a large number of Spanish adventurers flocked to Africa and America to search for gold and treasures. At that time, when searching for gold in the rivers of Ecuador, it was repeatedly found that there was a white metal mixed with gold, which was actually precious platinum. However, due to the underdeveloped science and low recognition ability at that time, faced with dazzling platinum, those colonial rulers called it "inferior broken silver" and abandoned it.
1748, Antonio Roya, a famous Spanish scientist, discovered silver-white natural platinum in Pinto River Gold Mine. After careful study, he found that natural platinum has very stable chemical properties, excellent ductility, high melting point and high relative density, which is obviously different from metallic silver. As a result, Anthony became the first scholar to study platinum in detail.
1780, a skillful craftsman in Paris made platinum rings, brooches and platinum necklaces for King Louis XVI and Queen of France. Therefore, Louis XVI and his wife became the first recorded people in the world to own platinum ornaments. Since then, the reputation of platinum has greatly improved, and it has leapt above gold ornaments, and it has been favored by the royal family, dignitaries and wealthy businessmen.
[Edit this paragraph] Application of Platinum with Different Purities
The hardness of pure platinum is small, so in order to increase the hardness, a certain proportion of precious metals such as palladium, rhodium and iridium must be added. Pt950 contains 5% palladium, rhodium and iridium, and its hardness is still relatively low, so it is generally used in plain platinum jewelry. Pt900 contains 10% palladium, rhodium and iridium, and its hardness is just suitable for inlaying ornaments. At present, most platinum rings are made of Pt900; However, a few manufacturers use Pt950 to make platinum ring holders.
[Edit this paragraph] Platinum and related issues
Platinum is one of the rarest jewelry metals in the world. Only a few places in the world, such as South Africa and Russia, produce platinum, with an annual output of only 5% of gold. Tons of ore, after 150 processes, takes several months, and the extracted platinum can only be made into a simple ring weighing several grams. So rare, no wonder owning platinum feels precious. Many famous designers call platinum "the king of precious metals"!
The following are its wide applications and frequently asked questions:
1, platinum has strong oxidation resistance and high melting point, so it is also used to make spacesuits. As a catalyst, platinum is widely used in automobile exhaust purification devices and plays an important role in protecting the environment.
2. During the Second World War, platinum had great military use, because it was a good catalyst with high melting point. The U.S. government once banned the non-military use of platinum.
No one's skin is allergic to platinum. Platinum can be used as the electrode of electronic pulse regulator and directly inserted into human heart to treat patients with arrhythmia.
Platinum can also be used to make waterproof watches with diving depth of 200 meters.
Why is platinum better than Huang Jingui?
Because platinum is a rarer metal than gold, the annual production of platinum is only 5% of that of gold, and the processing of platinum also needs a higher technical level.
Why is it safest to use platinum to set diamonds?
Platinum is tougher than ordinary metals, can be firmly embedded with diamonds, and is safe and not easy to fall off. Therefore, it is safer to embed high-quality diamonds in platinum. For this reason, in the international insurance industry, the premium paid by platinum diamond-encrusted jewelry is lower than other diamond-encrusted jewelry, and the natural white luster of platinum can better set off diamonds.
Platinum is the symbol of platinum. Pt900 stands for platinum jewelry with a purity of 90%. The higher the purity, the more expensive the platinum is.
Platinum is expensive, Huang Jingui.
In nature, platinum reserves are rarer than gold. The annual output of platinum in the world is far less than that of gold. The global jewelry industry consumes only 3% platinum every year. Coupled with the high melting point of platinum, it is more difficult to purify and smelt platinum than gold, and the energy consumption is higher. Moreover, processing platinum requires a higher technical level than processing gold. Therefore, platinum is a rarer and more precious precious metal than gold, silver and other precious metals. Platinum is better than Huang Jingui.
[Edit this paragraph] Platinum ornaments
Diamond inlaid with platinum can keep the pure white of the diamond, which will not lead to the yellowing of the diamond and reduce its price like gold. The natural white luster of platinum can better set off the brilliance and beauty of diamonds. Moreover, platinum is tougher than ordinary gold. Jewelry made of platinum, such as necklaces, is tough and reliable even if it is carefully processed. Gems such as diamonds inlaid in platinum are also the strongest, most reliable and safest, and inlaid diamonds are not easy to fall off.
Ultra-light platinum necklace has become a popular trend of Chinese jewelry. An ultra-light platinum necklace (1995) of 200 ~ 400 yuan is acceptable to ordinary wage earners. Moreover, platinum necklaces are short without pendants, simple and generous, and are deeply loved by women who have multiple chains for one person, one chain for one season or one chain for one dress. Experts believe that ultra-light platinum necklaces have the characteristics of elegant style and integration of eastern and western cultures, and will soon be popular throughout the country.
Platinum jewelry is mainly popular in developed countries and regions such as Europe, America and Japan. Among them, the Japanese prefer platinum jewelry most, and its sales account for about 75% of the total sales of platinum jewelry in the world, so it is known as the "Platinum Power".
China's platinum group mineral resources are few, and the reserves are less than 1% of the world's reserves, which can only meet a few percent of the demand and are mainly used in industry. The production of platinum jewelry started late. At present, only a few local manufacturers produce platinum jewelry.
Platinum, like other precious jewelry, should be stored separately from other jewelry to avoid contact, collision and scratches. It should be carefully cleaned regularly with jewelry cleaning equipment, or it can be sent to a jewelry store for professional cleaning.
Platinum ornaments
Diamond inlaid with platinum can keep the pure white of the diamond, which will not lead to the yellowing of the diamond and reduce its price like gold. The natural white luster of platinum can better set off the brilliance and beauty of diamonds. Moreover, platinum is tougher than ordinary gold. Jewelry made of platinum, such as necklaces, is tough and reliable even if it is carefully processed. Gems such as diamonds inlaid in platinum are also the strongest, most reliable and safest, and inlaid diamonds are not easy to fall off.
Ultra-light platinum necklace has become a popular trend of Chinese jewelry. An ultra-light platinum necklace (1995) of 200 ~ 400 yuan is acceptable to ordinary wage earners. Moreover, platinum necklaces are short without pendants, simple and generous, and are deeply loved by women who have multiple chains for one person, one chain for one season or one chain for one dress. Experts believe that ultra-light platinum necklaces have the characteristics of elegant style and integration of eastern and western cultures, and will soon be popular throughout the country.
Platinum jewelry is mainly popular in developed countries and regions such as Europe, America and Japan. Among them, the Japanese prefer platinum jewelry most, and its sales account for about 75% of the total sales of platinum jewelry in the world, so it is known as the "Platinum Power".
China's platinum group mineral resources are few, and the reserves are less than 1% of the world's reserves, which can only meet a few percent of the demand and are mainly used in industry. The production of platinum jewelry started late. At present, only a few local manufacturers produce platinum jewelry.
Platinum, like other precious jewelry, should be stored separately from other jewelry to avoid contact, collision and scratches. It should be carefully cleaned regularly with jewelry cleaning equipment, or it can be sent to a jewelry store for professional cleaning.
[Edit this paragraph] The meaning of platinum jewelry imprint
"Pt" is a unique symbol of platinum chemical elements and also a unique symbol of platinum jewelry composition. Platinum cannot be marked with the exclusive symbol "Pt". According to the regulations of the State Bureau of Technical Supervision, all platinum ornaments produced in China should be marked with the exclusive symbol "Pt".
Usually, the platinum content of platinum ornaments is expressed by a few thousandths of platinum content. At the same time, platinum content is also one of the basis for pricing platinum jewelry. Common platinum content marks are as follows:
Foot platinum: the percentage of platinum is not less than 990, and the mark "Foot platinum" or "Pt990" indicates that the percentage of platinum in jewelry is 99%.
950 Platinum: The percentage of platinum is not less than 950, and the mark "Platinum 950" or "Pt950" indicates that the percentage of platinum in jewelry is 95%.
900 Platinum: The percentage of platinum is not less than 900, and the mark "Platinum 900" or "Pt900" indicates that the percentage of platinum in jewelry is 90%.
In foreign platinum jewelry, the words "Pt", "Plat" or "PM" are usually engraved. There are standard journalists like platinum jewelry.
The platinum ornaments produced in China are printed with the words "Platinum", "True Platinum" and "Positive Platinum" in addition to the trade name. If the seal on the jewelry is "S" or "Silver", it is a silver jewelry. If the jewelry is marked with the words "red platinum" or "k platinum", it means it is not pure platinum jewelry, or it is not platinum jewelry at all.
[Edit this paragraph] Identification of Platinum and its Ornaments
Simple identification method
1, color
Platinum is silvery white or grayish white, which is between the colors of silver and nickel. Silver has a white luster and is easily oxidized with black spots or black; Fine and smooth texture; Hardness is lower than platinum.
2. Specific gravity
The proportion of platinum is significant, ranging from 15 to 19 or 2 1.4. The ratio of silver is 10.49. When you weigh platinum and silver ornaments of the same size by hand, you will find their differences.
3. Fire
The color of pure platinum remains unchanged after being heated or cooled by fire. After silver burns, its surface will appear moist red or black-red tone.
Step 4 bend
Pure platinum is easy to bend and recover; Low color, hard and brittle, not easy to bend.
Step 5 listen
When you knock, if you make a blank sound of "Toto", it is relatively pure platinum; If it makes a harsh sound and rhyme, it is low-color platinum.
6. Mercury wiping test
Using the property that platinum does not absorb silver, mercury is coated on the touchstone grinding road. If it is silver-absorbing, it is K platinum made of gold, silver and platinum.
7, nitrate test
Grinding the platinum ornaments to be identified on the touchstone, and covering the ground track with a layer of salt, which does not need to be tightly covered; Then, drop nitric acid on the salt until it is soaked; Add some hot paper ash to the salt to play a catalytic role. After 20 minutes, wash the salt and nitric acid with clear water. After work, look over here. If there is no change, its color is about 99%; If there is trace acid, its color is about 95%; If the trace amount of nitric acid is large, its color is about 80 ~ 90%; If a layer of grinding road is corroded, the trace becomes gray, and its color is about 70%; If all traces disappear, it is fake platinum.
8. Identification of spontaneous combustion of gas lamps
Put the platinum ornaments to be identified on the gas stove. If it is real platinum, after a minute or two, the ornaments will turn red and the gas lamp will ignite automatically. If the jewelry is not platinum, there is no such reaction.
9, hydrogen peroxide reaction method
Platinum is a good catalyst with unique catalytic effect. Using this characteristic, platinum can be quickly identified. Hydrogen peroxide reaction method is commonly used. The specific method is as follows: Take a little powder of the test object and put it into a plastic bottle filled with hydrogen peroxide (H2O2). If it is platinum, hydrogen peroxide will immediately roll and bubble, decomposing a lot of oxygen. After the reaction, platinum is still intact and can be recycled (only accelerating the decomposition); If it is fake platinum or other white metals, such as lead, silver and aluminum, there is no such reaction.
10, other
You can also ask the geological department for electronic probe testing.
[Edit this paragraph] The difference between platinum and similar metals
Platinum is characterized by silvery white color and streaks, hardness of 4 ~ 4.5, specific gravity of 15 ~ 19 or 2 1.4, stable chemical properties, insoluble in ordinary acids and easy to distinguish from similar metals.
1, the difference between platinum and silver
Platinum and silver ornaments are very popular in the market and have always been the favorite ornaments of many women. Because platinum and silver have many similarities, it is necessary to distinguish them.
Platinum is different from silver in hardness, specific gravity and chemical stability. Generally, the following simple methods are used to distinguish them.
(1), comparative color, hardness
Platinum is silvery white or grayish white; Hard texture, Mohs hardness of 4 ~ 4.5. Silver is white; The texture is smooth and delicate, and the Mohs hardness is 2.5 ~ 2.7, which is softer than platinum and can be left with nails. Inelastic, the foil is easy to bend by hand and difficult to recover.
(2) Test specific gravity
Platinum has high density and high specific gravity. Although silver is silvery white, its relative density is 10.53g/cm3, and its specific gravity is10 ~1/only 1/2 of platinum. The same volume of silver is half as light as platinum. Generally speaking, platinum and silver can be roughly distinguished by hand.
(3), chemical methods
Silver is chemically unstable, soluble in nitric acid, and emits nitrogen dioxide gas. Platinum is insoluble in nitric acid, but it can dissolve quickly in heated aqua regia. At room temperature, its dissolution rate is extremely slow, which is generally difficult to detect with the naked eye. Put the platinum sheet on the touchstone and drop a little mixture of nitric acid and hydrochloric acid. If the debris still exists, it is platinum; If the debris dissolves and disappears, it is silver.
2, the difference between metal lead and aluminum
Platinum differs from lead and aluminum in different deformation characteristics and high specific gravity. Metal lead and aluminum are inelastic and cannot be recovered after deformation; And the specific gravity is much smaller than platinum. The specific gravity of lead is 1 1.36, and that of aluminum is 2.7, which are about 1/2 and 1/8 of platinum, respectively, and can be distinguished by hand weighing.
3. The difference between platinum and platinum
Platinum is an element and platinum is a mixture. Platinum: Platinum is chemically more stable than gold and its price is higher than that of Huang Jingui. Used to make high-end jewelry. The "pt900" or "pt950" seen on jewelry products represent that the platinum content in jewelry is 90% and 95% respectively.
Platinum, commonly known as platinum, is pure white. The reserves of platinum in nature are scarcer than gold, so its price is higher than that of Huang Jingui. Platinum can keep the true colors of white diamonds, and it is very strong. It is the best material for setting diamonds, and it is diamonds that make platinum a superstar among precious metals in jewelry. In China, the colors used in jewelry inlay are mostly Pt950 and Pt900, and Pt900 is the most commonly used.
According to the provisions of the Purity and Naming Method of Jewelry and Precious Metals, the total content of platinum and palladium shall not be less than 950%. Platinum jewelry is crowned with platinum or Pt with a purity of one thousandth. For example: 990, Pt990 or enough platinum.
Platinum is soft, so if you want to set diamonds, you must alloy it. Even if 5% alloy is added, Pt can be hardened to meet the processing requirements. Part of the added alloy component must be platinum group metal.
The allowable purity in Japan is 1000.950.900.850, and there may be a slight (0.5%) negative difference. The purity of 850Pt is generally used for chains, and Pt900 is the most commonly used purity. As Japan is the most important export market in Hong Kong, Hong Kong adopts Japanese standards.
The United States stipulates that if the purity is called Pt, it must contain at least 50% platinum and 95% platinum group metals. Purity with platinum content higher than 95% can be marked with Pt. Jewelry with platinum content between 75% and 95% must also be marked with platinum group metals. Jewelry with platinum content between 50% and 75% must be marked with the name and content of platinum group metals. Such as 585 platinum and 365 palladium (585 platinum and 365 palladium). Only the United States allows "K platinum" alloy.
Specific gravity of Pt-Pd alloy: Pt950-20.64pt900-19.88pt850-19.5438+08.
K the difference between platinum and platinum. Strictly speaking, K platinum cannot be equated with platinum. Platinum is a natural white precious metal. At present, it is the highest price among all precious metals in jewelry. All platinum ornaments on the market have the symbol "PT", which is the English abbreviation of platinum. Platinum is a white alloy made of gold and other metals. The so-called 18K platinum is actually composed of 75% gold and 25% other metals. Therefore, K platinum cannot be marked with the "PT" mark, and only gold and purity can be marked according to its purity. For example, 18K platinum can only be stamped with "18K" and "G750". So, how to simply distinguish the two? First of all, it is more reliable to buy these precious jewelry in big shopping malls. The most important thing is to read the label clearly and see whether the jewelry is marked with "K" or "PT".
When purchasing platinum jewelry, the operator should be required to issue an invoice, and the invoice should indicate whether it is platinum or white 18k gold. It is best to indicate the weight of the jewelry, so it is easier to claim compensation in case of fraud.