Gold is a mineral, a brief message on the topic and a description of its properties (grade 4, the world around us)

Gold, along with silver and platinum, belongs to the noble metals that are not covered with a film of oxides in air. They are rarely found in nature, which is why they are called precious. Gold jewelry dating back to 4.5 thousand years BC. BC, found in Egypt. The first gold coins appeared in the 7th century BC. e. in the territory of modern Western Turkey. The message about gold describes its properties, uses and occurrence in nature.

Description of gold

The properties of gold depend on its composition. Natural gold contains impurities of other metals - silver, copper, iron, lead. Most often, native gold is found mixed with silver. Pure gold is obtained industrially.

Pure gold is a yellow metal that is so soft that it can be scratched by a fingernail or the tip of a ballpoint pen, but is easily polished. Gold is a very heavy metal. For example, a ball with a diameter of 4.6 cm weighs almost 1 kg.

Gold conducts heat and electricity well. Under natural conditions, it is not destroyed by acids and alkalis. There is one exception, discovered in the 14th century: a mixture of nitric and hydrochloric acids, called aqua regia, easily dissolves gold.

Varieties and characteristics

A fossil such as pure gold has extraordinary softness. Because of this, the material is very easy to damage, even if you run your fingernail over it, it can get scratched. In order to give the metal strength and reliability, certain alloys are created with the addition of silver, platinum and other elements that make the compound harder.

Due to its high level of density, this mineral is very easy to extract from land and water bodies. If we compare in terms of heaviness, this precious metal takes an honorable 6th place, inferior to the following elements:

Platinum;
Osmium;
Iridium;
Rhenium;
Plutonium.

Excellent ductility can also be highlighted. It is possible to make gold sheets that are only a few millimeters thick. This element has proven itself well as a conductor that conducts electricity and heat without difficulty. Under normal conditions, this material is not affected by acids, and as a result does not oxidize.

Dissolution in aqua regia.

The only thing that can be used to dissolve such minerals, which in their characteristics and composition resemble gold, is aqua regia, as well as some chemical compounds that contain sodium. Most often, this material is distinguished by color. It depends on which metals are added to the alloy.

The common yellow color seen on jewelry is a mixture of gold with silver or copper. If there is a slight tint of red, more copper particles have been added. In Europe, products with lemon-yellow colors are very popular and widespread. This indicates that manufacturers gave greater preference to silver.

If you add nickel, platinum or palladium to the alloy, you get white gold. If the amount of nickel is excessively large, then such a product may cause an allergic reaction. Red gold has gained great popularity in Rus'. It was made by adding copper. And to make it shine, a certain amount of silver was added. There are also items in other colors.

Also, if the composition is known, then the sample can be determined. In Russia there is a specially developed sample scale.

No. 375. The base metal is 30%. The rest of the volume is occupied by copper and silver particles. This alloy tends to tarnish quickly, but can be polished very easily.

No. 500. Half of the entire composition is noble metal, and the rest is additional elements. This option is very difficult to melt and over time loses its natural shine.

Types of hallmarks on Russian gold samples.

No. 585. Gold occupies 59%. The percentages of other metals may differ from each other.

No. 750. The alloy contains the same elements as the 585 sample, but gold occupies 75%. The shine lasts much longer than all previous samples and there is a vibrant variety of colors.

No. 999. This sample is considered the rarest and most expensive because it consists of pure gold.

In other countries, this scale may differ slightly, but these differences will not be too significant.

Where is gold found?

Gold deposits suitable for mining are divided into 3 groups.

Gold in quartz veins or other rocks. Extraction is carried out in quarries and mines.
Gold nuggets in placers. A placer is a deposit that has been washed away by a stream or river. Gold, along with the destroyed rock, is carried away by water and then settles in the riverbed. Nuggets can be large, weighing several kilograms, and in the form of golden sand. The largest of them, especially those with a bizarre shape, are kept in museums. It is mined using special equipment in the riverbed.

Rice. 1. Nugget “Hare ears”.

Waste rock dumps after gold mining. Currently, the latest methods for extracting low metal content are being used, so the dumps have turned into a “mineral resource”.

Some gold can be recovered from old radio components. To do this you need to know chemistry well, but some craftsmen manage to do it at home.

Rice. 2. Gold-containing radio components.

Uses of gold

Refined gold in the form of bullion acts as a government reserve in case of an emergency. The United States has the largest reserve - more than 8,000 tons. As of January 1, 2021, Russia, with a reserve of about 2,300 tons, ranks 6th in the list of countries in the world.

Gold alloys of gold, silver and copper are used in jewelry. The gold content can be determined by the hallmark - the stamp on each product. For example, a figure of 0.875 indicates a gold content of 87.5%.

It is believed that 11% of the world's gold supply is owned by women in India in the form of jewelry, where gold items are a gift for all occasions. This is a wedding, birth, diploma defense, anniversary, new position. Gold passes from heir to heir and accumulates in the family.

Rice. 3. Indian gold items.

Applications of gold

Statistics say that 90 percent of the gold mined is stored either in banks as the country's gold reserves, or with individuals in the form of jewelry, coins and other items. Only 10% of mined gold is used in industry.

In electrical engineering, gold is used to cover the surface of contacts, connectors, and also as solder.
Gilding of metals is used to protect them from corrosion.
Gold is contained in the shell of a neutron bomb.
In the food industry, gold is registered as a food additive E175.
Gold is used for casting glass. A thin gold film in the glass protects against infrared radiation. And the current passed through such a layer gives the glass anti-fog properties. This is how glass is made for ships, ships, locomotives, and airplanes.
In medicine for the manufacture of crowns and dentures, for the manufacture of medicines.
In cosmetology – for skin rejuvenation.

But most of all gold is used for making jewelry.

What have we learned?

Gold is a valuable metal and is widely used. The article briefly describes the characteristics of the metal and its location in nature. Gold is used in jewelry, industry, dentistry, in the production of medicines, and in the treatment of cancer, which can be discussed in a report or essay on the topic “Gold. Properties and Application" for 4th grade.

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"Golden" story

This story begins in ancient times, because it was this material that gave rise to a new era - the era of metals. People then praised it for its unusual “sunny” color. It was believed that only people of noble blood could possess this metal. This was prestigious, because gold has always played an important material role. It could be exchanged for anything, and women decorated their hair and clothes with it. In addition to the pros, there were also cons. Gold is wealth, and wealth often led to unrest and war. The desire for independence was stronger than humanity, and people died. A lot of people.

Abstract on the topic: Gold is a mineral

We have prepared several short messages about such a mineral as gold. Find out when this precious metal first began to be mentioned, its properties and where it is mined. Use the material to prepare school essays and reports.

Message 1

Gold is a fairly noble and beautiful metal, yellow in color. It attracts many with its brilliance and grace. For us common people, we know gold for its beautiful jewelry. Many gold rings, chains and brooches were created by craftsmen using this metal. It turns out that gold has been known to people since ancient times. Mentions of it can be found even in a book such as the Bible. Weapons were decorated with gold, expensive jewelry was made for women, gold bars were given as gifts and, of course, coins were made from it.

If we consider gold in its pure form, then this material will be quite soft. It is quickly damaged, almost from a touch. Therefore, experts, in order to make gold products stronger, decided to add platinum, copper and silver to it. Gold and its properties have always interested people. When experts began to study the material in more detail, they noticed that gold conducts well, not only heat, but also electricity. Gold cannot oxidize; it can only be dissolved if you use a solution of sodium or potassium cyanide. Gold began to be classified by color. Each of its colors always depends on the other metals added to the composition of gold. We are used to thinking that ordinary jewelry contains gold, but this is not true. Almost all gold jewelry consists directly of this metal, plus an alloy of copper and silver. If the alloy is like this, then the color of the decoration will be yellow. If you add a little more copper to gold, then all products made from it will have a reddish tint. People know white gold, lemon yellow gold, blue gold and even green gold. And every time people add other metals to the main composition of gold.

Of course, gold is one of the most ancient metals. Its mining began when people discovered copper deposits. Gold has always been a very rare material, so it was valued and even fought for its deposits. At one time there was even a gold rush that covered vast territories. People were chasing gold, each trying to find more than others. It is believed that the largest gold deposits are located in South Africa, China, Peru, Australia and the USA. Russia also has some gold reserves, which are located in the Amur region, Chukotka and the Krasnoyarsk Territory. Gold mining methods have always depended on the types of gold deposits.

If gold had many impurities, they tried to extract it using regeneration. Mining for nuggets has always entailed the use of a panning method. Mining for gold has always been a painstaking and time-consuming job, but many people enjoyed it and it was a great way to get rich for a long time. It is believed that today almost the entire world's gold supply is stored in the form of gold bars in banks, the rest is represented in jewelry and some precious items. People have learned to use gold in many areas and areas of life. Gold is well used in industrial and economic fields. It is widely used in medicine, cosmetology and even in the manufacture of glass for aircraft and ships. Still, we are accustomed to thinking that gold is beautiful jewelry on display in jewelry stores, the purchase of which brings joy to many people.

Message 2

Gold is one of the few precious metals. Humanity has been using gold since long before our era. But it was not used as an element of luxury. Ancient people used gold as a weapon. They used gold to hunt animals. Tips for spears and arrows were mainly made from gold because metal was difficult to find.

Now gold is more often used as an element of luxury. A lot of different jewelry, rings, earrings and many other types of jewelry are made from gold.

Despite the fact that gold is one of the softest metals, its melting point exceeds a thousand degrees. While other harder metals have a melting point that is two times lower. Gold is also a very good electrical and thermal conductor. Despite this, for some reason, gold is not used as a radiator. But they are very widely used in cables.

Gold also has a fairly high ductility. To explain with an example, from one ounce of gold you can get as much as 80 kilometers of gold thread less than a human hair thick. By the way, very high-quality and durable threads are obtained from gold threads.

Gold is a metal that is extremely difficult to mine. But this does not mean that there is little of it on our planet. There is an assumption that there is gold even in the atmosphere, but it is invisible to our eyes. Gold is the first metal to be discovered by man. The main concentration of gold is in the metallic core of the earth. That's why it's so hard to get. Over the past five years, humanity has made a huge leap in gold mining. Gold is also mined in various streams and rivers. This is how the largest nugget was found, weighing 72 kilograms. He was only five centimeters underground.

The largest gold mining continues to this day in the Republic of South Africa. More than five hundred tons of gold can be mined in South Africa per year. But this is not so easy to do. To bring this gold to the surface, seven hundred tons of other rocks have to be crushed. Tons of water are used to wash the gold ore. A large amount of fuel and various chemicals are wasted. This gold is mined in a mine three and a half kilometers deep.

Now an ordinary person can easily purchase any gold jewelry for a fairly large sum. After all, gold is so difficult and expensive to mine. But what can you not do for such beauty?

Message 3

Gold is a precious metal with a distinct golden color and shimmer. In the periodic table it ranks 79th. People started looking for gold many years ago. This metal, without any impurities, is very soft and elastic, because of this it can easily change its shape. To make it stronger, copper, silver, and platinum are added.

This metal has a high density and is easy to mine. It is very heavy on its own. Plastic, perfectly conducts electricity and heat. Gold can withstand everything; it does not oxidize. It can only dissolve in a solution of Na or K. Gold can be identified by color, the color depends on what is added there. If you look at gold without impurities, then it is a bright sand color, but if it has a tint of red, then there is a lot of copper present. If the gold is bright yellow with a lemon-colored tint, then there is clearly a lot of silver present there. It can also be light silver in color if platinum, nickel, or palladium is added.

Gold also comes in green, black, blue, and purple. Each gold has its own hallmark, it depends on the ligature. Gold has its own research and assay scale. It is the rarest metal. It began to be mined a long time ago at the same time as copper. Scientists suggest that over the course of their entire life on earth, people have mined 165 tons of gold. If you pour all this gold into one ingot, you will see a cube 20 meters wide. The best gold deposits are in China, Australia, the USA and South Africa. But there are also such places in Russia: Chukotka, Krasnoyarsk Territory, and Amur Region.

There are different methods for mining gold. Which method will be used depends on the type of deposits. To obtain a nugget, the washing method is used. Where dispersed gold is used, the method of dissolution in mercury is used. If the ore contains gold, there is a huge content of impurities, then it is mined by regeneration. But at the same time they use high technology. Statistics show that 90% of the gold that is mined is stored in a bank, or with individuals in the form of all kinds of jewelry. The remaining 10% is used in industry.

Mining for gold is very hard work. After all, there is very little of it. And for a huge piece of land, very little gold can be mined there. Suppose there is a large amount of this metal in the ocean, but it is almost impossible to find it, because it is scattered along the bottom. It's the same on land. But of course there are also rich deposits. This is one type of metal that has conquered the planet and become noble and number one on earth.

Message 4

Gold is not only an element of the periodic table. It is also a very beautiful and quite mysterious metal of noble yellow color. It has both material and historical value.

Story

Properties of gold

Gold, despite its elegance and beauty, is a very heavy metal. It is not exposed to virtually any chemical influences, which is why it has earned the title “noble metal”. It is very soft and ductile, so the number of different types of gold products is constantly growing, but its excessive fragility does not allow it to be used in its pure form - only with the addition of silver or copper. By the way, their color directly depends on the percentage of these materials in the product. Good thermal conductivity also allows the use of gold in the manufacture of various types of devices.

Production

Mining gold is not an easy task, because despite the fact that it is the most popular metal, it is also low-concentrated. That is, there is a negligible amount of it in a large space. For example, there is a lot of this rock in the World Ocean, but it is so widely scattered across the ocean floor that it is almost impossible to get it. The same applies to the earth's crust. But there are also rich deposits. The main thing is to know where to look. The types of gold mined also directly depend on the location of mining. In the ground, the pieces of gold are crystal-shaped, and those closer to the water are round.

At all times, gold mining has been a very profitable business, but in reality there is not so much of it.

Message 5

Gold is the only metal that, in its pure form, has a beautiful bright yellow color. It has a good shine, which increases when polished. Density - 19.3 g/cm3, melting point - 1063°C, Brinell hardness - 20, color - yellow.

The average gold content in the lithosphere is 4.3 x 10-7% by mass.

People have been mining gold since time immemorial. There are several main methods for extracting gold, the main ones being washing river sand and extracting gold-bearing rock in mines. Gold can be extracted from gold-bearing rock by amalgamation, chlorination, or cyanide.

In total, more than 140 thousand tons of gold have been mined by humanity. Of this, more than 40% went to jewelry, and 12% to technical purposes.

Collected in one place, gold mined throughout history would form a cube with an edge equal to 19 m, that is, the height of a five-story building (while the ore and sand from which this gold was extracted would represent a mountain more than 2.5 km high). The gold currently mined throughout the world in one year would fit in a medium-sized room.

There are primary deposits of gold, placers into which it falls as a result of the destruction of ore deposits, and deposits with complex ores in which gold is extracted as an associated component.

Major gold mining countries: South Africa, USA, Australia, Canada, China and Russia.

In Russia, Erofey Markov is considered the first gold miner, a monument to whom stands in the city of Berezovsky near Yekaterinburg.

Natural or native gold, as a rule, is not pure and its purity ranges from 500 to 950. The main impurities in native gold are silver and copper, as well as many other elements, therefore, to achieve high purity, it is subjected to refining (purification) at special enterprises.

Refined gold is produced in bars of various weights - 1 gram, 5 grams, 10 grams, 50 grams, 100 grams, 500 grams, 1,000 grams, 12,000 grams, or in the form of gold coins weighing from 1/2 gram to 5, 10 and even 100 kg, as well as in the form of tapes, strips, foil, wire and other semi-finished products.

The gold content in bars and gold coins is about 99.99%, the remaining hundredths and thousandths of a percent are impurities (lead, iron, antimony, bismuth, copper or silver, etc.). The amount of impurities is regulated by GOST.

Gold is a very ductile and soft metal; it can be rolled into sheets up to 0.0001 mm thick. (“leaf” gold), and from one gram draw a wire 3.5 km long.

Gold does not oxidize in air and is resistant to moisture, insensitive to acids, alkalis and salts. The exceptions are a mixture of hydrochloric and nitric acids in a ratio of 3/1 (regia vodka), sulfuric acid in combination with manganese or nitric acid, as well as hot selenic acid, in which gold dissolves quite easily.

When combined with mercury, gold forms an amalgam (once this property of gold was used for “hot” gilding of jewelry: the jewelry was rubbed with amalgam and heated over hot charcoal; when heated, the mercury evaporated, and a thin layer of pure gold remained on the product).

In the jewelry industry, pure gold is used to form alloys of precious metals. Gold alloys are ideal materials for making jewelry. Unlike too soft pure gold, they are more durable and wear-resistant, and when adding various alloys, they easily change color to white (white gold), red, green, pink, etc.

The importance of gold for the economy

Gold as a mineral

Let's return to quotes about gold.
“ There will always be gold, gold will be money when the dollar, euro, yuan and others will only be memories. »

American politician, Richard Russell.

Yes this is true. Let's compare the change in the exchange rate of the dollar and gold.

Dynamics of growth in gold prices 999.9 since 2000

Year	1 dollar	1 oz gold
1999	26 rubles	279 dollars = 7,254 rubles
2005 year	28 rubles	445 dollars = 12,460 rubles
2010	31 ruble	1,225 dollars = 37,975 rubles
2015	61 ruble	1,160 dollars = 70,760 rubles
2021	75.24 rubles	1,770 dollars = 133,192 rubles

The table shows rounded values.

It is obvious that the growth of the dollar is less intense than that of gold. If we study additional statistics, we will see the instability of currency growth. Gold has direct growth, absolutely not subject to the euro, dollar or yuan.

What can we say about the ruble? If it is one of the most unstable currencies. Compared to the dollar or euro, it means practically nothing. He is completely dependent on politics, economics, and world events.

Draw your own conclusions about where and how to store your savings...

How gold is mined

Mining floating gold from alluvial placers manually using a tray
On our planet, gold can be found everywhere, it is present even in river and sea water. However, often the concentration is so negligible that extracting the element is simply not economically feasible.

Initially, the main method of extracting precious metal was the mining of placers. Extraction was carried out using a very primitive method, by washing the rock mass in a special tray manually. Since gold is heavier than many rocks, it settled on the bowl. Since ancient times, mining has been carried out in mines. How is gold mined today, what technological processes are used to extract it from rock?

To this day, ancient adits, reaching a depth of 100 meters , where gold was mined 2000 years ago .

In the modern mining industry, all development is mechanized and carried out using specialized equipment.

The technological chain of placer development is as follows:

river channel diversion;
stripping operations (removal of the top layer of rocks);
extraction of gold-bearing rock;
washing;
cleaning;
enrichment;
remelting

In cold regions, such production is seasonal; in winter, flushing stops.

Mass mining is carried out in the development of primary deposits using open (quarry) or closed (mine) methods (see Discoveries in gold mining).

Gold-bearing rock also goes through the stage of extraction to the surface, crushing, enrichment and separation of gold from impurities.

Metal magic

The description of gold also contains its magical properties. The metal is considered a powerful and very strong solar element. The material influences strong-willed individuals, increases their confidence and strengthens their internal strength. It is useful to wear gold jewelry for those who have masculine signs in their cosmogram. It is recommended to wear jewelry for Leos, Taurus and Aries. To improve well-being, the metal will be useful for Gemini, Sagittarius, Aquarius and Scorpio. It has no effect on other zodiac signs.

Gold attracts wealth, it attracts new money, it gives a person a strong character, a sense of courage, and nobility. Under its influence, people become more purposeful and achieve significant success in the material sphere. Since ancient times, medallions in the shape of the sun or star have been made from metal. They served as talismans for those who worked underground. The decoration protected them from landslides and other accidents, gave them vigor and instilled a sense of security.

The medallion should be worn in the solar plexus area. This will enhance all its properties, and the product itself will become reliable protection against any love spells and the effects of all types of magic. But it is not enough to simply put on jewelry; you must sincerely believe in its properties. With its help, you can force yourself to achieve goals that previously seemed unattainable.

The physical, healing and chemical properties of gold make it popular among jewelers and buyers. Although the market for products made from precious materials has been experiencing an excess of supply over demand for several decades, which is due to the high cost of jewelry.

Annual production of the valuable material is declining, since all known deposits are practically exhausted. In addition to jewelry, metal is used in the field of investment and industrial production, electronics and circuit design, because its high ductility and malleability make the work of craftsmen easier.

Production

At all times, gold mining has been a very profitable business, but in reality there is not so much of it.

This metal, which conquered the earth and became one of the most important metals, will never lose its value.
People have tamed it. We learned to mix and change, make beautiful things and exchange them for useful ones. It will always remain metal rich and noble. If this message was useful to you, I would be glad to see you in the VKontakte group. Also, thank you if you click on one of the “like” buttons:

Discovery in nature

In natural conditions, gold is often found. It makes up almost 5% of the entire lithosphere of the planet. The high price of the metal is due to its labor-intensive extraction, even with special equipment. There are many types of rocks that contain small particles of gold, but it is represented by dispersed dust. Interesting facts are known from history that people found large deposits of fossils simply under layers of earth.

The chemical element is formed in the earth's crust under the influence of temperature changes. The material is extracted from iron and mineral ores. The metal is mainly found in the form of nuggets, but in nature you can find its compounds with silver, bismuth, copper, selenium or antimony. Known natural solid solutions are called:

electrum (silver gold);
aurocuprid (copper gold);
porpecite (palladite gold).

There are secondary deposits of the substance, which are the result of the destruction of primary compounds. The reasons for the origin of such fossils may be:

physical (wind, water, temperature fluctuations);
chemical (chemical reactions);
biological (bacteria and other microorganisms).

A fairly large amount of the chemical element is found in seawater, but extracting it from there is unprofitable. The scattering of material is similar to sand, which is carried by the current over long distances from the primary deposit. A small amount of pure substance can be detected even in ordinary running water.

Today the precious metal is mined in many countries around the world:

Russia;
China;
Australia;
Peru;
Canada;
USA;
SOUTH AFRICA.

Gold has been discovered in Ghana, Indonesia and Mexico. These countries supply gold to the world metals market. On the physical map it is marked with a symbol in the form of a circle with the left half shaded.