Main topic information 1
Vocabulary/new concepts:
Minerals and rocks represent a vast natural wealth. Minerals are naturally occurring solid inorganic substances and have a particular chemical structure and physical properties. They are the basic building blocks of rocks. A rock may consist of different minerals.
Fossil fuels – coal, oil and natural gas are formed from the remains of dead plants, algae and animals that lived millions of years ago. Under the influence of high temperature and pressure below the earth’s surface, these remains are converted into organic substances, which over a long period are converted into fossil fuels.
The Mohs hardness scale is used to measure and compare the hardness of minerals. The hardest mineral is diamond with a hardness grade of 10.
The carat is a unit for measuring the weight/mass of gemstones, in particular diamonds. One carat is exactly 200 milligrams. It is a convenient unit for measuring and comparing small weights, such as those of gemstones. It is widely used in jewellery.
Why do people from ancient times until today like to wear jewellery? What materials are used to make them?
Since ancient times, people have made and worn a variety of jewellery – necklaces, earrings, rings and bracelets – believing in the power, symbolism and healing properties of different minerals. Jewellery was associated with both the religious beliefs and the social status of its owner. Particularly popular to this day are diamonds, ruby, sapphire, emerald, amethyst, various types and colours of quartz, and beads. With their various colours, shapes, brilliance, hardness and durability, they attract us with their natural beauty and connect us with nature.
The most commonly used materials for the production of jewellery were and still are gold, silver and copper. They feature a variety of shapes, styles and ornaments, often incorporating precious stones and minerals.
Source: https://bg.wikipedia.org/wiki/%D0%92%D0%B0%D1%80%D0%BD%D0%B5%D0%BD%D1%81%D0%BA%D0%B8_%D1%85%D0%B0%D0%BB%D0%BA%D0%BE%D0%BB%D0%B8%D1%82%D0%B5%D0%BD_%D0%BD%D0%B5%D0%BA%D1%80%D0%BE%D0%BF%D0%BE%D0%BB#/media/%D0%A4%D0%B0%D0%B9%D0%BB:Or_de_Varna_-_Bijoux.jpg
On the photo: Part of the gold finds of the Varna necropolis in Bulgaria, dated to the middle and second half of the 5th millennium BC. More than 3,000 objects weighing a total of 6.5 kg were found there. This is the oldest worked gold on earth and is much more than all the gold that has been found from the Stone Age period in the whole world. There are 28 types of gold jewellery in this hoard, and the purity of the gold is between 21.5 and 23.5 carats – out of a possible 24.
In addition to gold, copper ornaments, jewellery made of various minerals and semi-precious stones, numerous pottery vessels, copper, stone and flint tools, and idols made of bone, clay and marble-more than 30 thousand objects in all were found.
The archaeological site is one of the most remarkable and significant monuments of prehistory in the Balkans and Europe. You can learn more about it at:
https://goldminebg.eu/%D0%B2%D0%B0%D1%80%D0%BD%D0%B5%D0%BD%D1%81%D0%BA%D0%BE%D1%82%D0%BE-%D1%85%D0%B0%D0%BB%D0%BA%D0%BE%D0%BB%D0%B8%D1%82%D0%BD%D0%BE-%D1%81%D1%8A%D0%BA%D1%80%D0%BE%D0%B2%D0%B8%D1%89%D0%B5/
What is the relationship between minerals and fossil fuels?
Minerals are inorganic substances formed naturally by various geological activities over millions of years. They have a crystalline structure, a particular chemical composition (can be an element, e.g. gold, or a compound, e.g. quartz) and physical properties (hardness, colour, density, lustre, etc.). Scientists believe that the diversity of minerals is due to chemical reactions on a biological basis, volcanic activity, movement of tectonic plates, and interaction between water and rocks – in short, it is linked to the evolution of life on the planet. Most of Earth’s minerals are rare and occur in five or fewer places on the planet.
Source: https://depositphotos.com/photo/set-various-blue-unpolished-stones-names-corundum-chrysocolla-iolite-apatite-354368264.html
Rocks represent minerals bonded together in different ways. The properties of rocks depend on the type and quantitative ratio of the minerals that make them up. They are a huge natural wealth that is involved in the reproduction process of the national economy.
Mineral resources are unevenly distributed concentrations of inorganic materials found in the earth’s crust. They are mostly extracted for economic purposes, and used in many industries such as construction, energy, agriculture, and manufacturing. Despite their significant benefits, mineral resources must be extracted and used wisely because they are a limited and finite natural resource. It is very important to monitor the environmental impact of mining activities, which can lead to pollution and habitat destruction.
Types of natural resources
- Energy resources – coal, oil, natural gas, uranium, thorium, etc. From them, the energy needed by mankind is extracted: thermal, mechanical,and electrical.
- Metallic mineral resources – extracted from iron, copper, tin, chromium and other ores. Ore minerals contain compounds of metals and are used to produce the corresponding metals. Depending on the composition of the metal compounds in them, they are divided into the following groups of ores:
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- Ferrous metals: iron, manganese, etc. They are the main component of steel, are obtained by processing iron and are used in metallurgy, construction, automotive and other industries;
- Non-ferrous metals: lead, copper, zinc, tin, aluminium, titanium. They do not have large concentrations of iron in their composition. They are widely used in electronics, in non-ferrous metallurgy for the production of alloys, in jewellery;
- Precious metals: gold, silver, platinum and palladium. They do not combine in nature with other elements, their reserves are limited and therefore very valuable. They are mainly used in electrical engineering, electronics, automotive, petrochemicals and jewellery;
- Rare earth elements: include a group of 17 chemical elements from the periodic table. They are rare in large deposits and difficult to obtain. They have unique properties that are indispensable for the production of many modern technologies, such as smartphones, electric and hybrid cars, military equipment, medical equipment and wind turbines.
- Non-metallic mineral resources – these are non-ore minerals from which metals are not extracted. They are used in different economic activities such as industrial and chemical raw materials, building materials and raw materials for the production of building materials, in jewellery. For example:
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- Building materials: limestone, gypsum, sand, gravel, clay, granite, kaolin, marble, zeolites, etc.
- Chemical raw materials: rock salt, potassium salt, phosphates, gypsum, barite, sulphur, graphite, fluorite, etc., which are used to produce fertilizers and chemicals
- Abrasives: corundum, diamond, etc., used for grinding and polishing. Diamond has the highest hardness among natural minerals and finds application in the manufacture of cutting tools
- Precious stones: these are naturally formed mineral crystals such as diamond, ruby, sapphire, emerald, topaz, amethyst, quartz and many others, which after processing – cutting and polishing, are used in jewellery. They differ from each other in origin and other qualities such as colour, transparency, hardness, size, absence of blemishes, rarity and carat. They have attracted the attention of people since ancient times, being a symbol of wealth, power, prestige, and beauty. They have been used as talismans, in magical practices, in jewellery art. They are believed to have certain healing properties on certain organs and areas of the human body and to charge us with the energy inherent in a particular stone.
It is a curious fact that Leonardo da Vinci strongly believed in the power of amethyst. He believed that this gemstone helped dispel evil thoughts and had the power to increase a person’s intelligence.
In Egypt and Asia Minor, as early as 3000 BC, amethyst was one of the most commonly used gemstones to create precious objects. In the Middle Ages, it was considered much more valuable than diamond and was set into the rings of nobles and royalty as a symbol of absolute power.
There are also many symbolic meanings of amethyst associated with religion. Because of this it was used in the decoration of churches and even today it is the stone of the rings of bishops.
The most beautiful amethysts are mined from Brazilian deposits, where bright violet crystals up to 30 cm in length can be found.
Around 20 billion tonnes of materials are currently mined and transported worldwide each year. Of these, 80% are construction raw materials, over 10% are minerals and the rest are ores. Production is increasing by around 4% a year, so that it doubles every 15 to 20 years. If trends in mineral extraction remain unchanged, an earlier expert forecast in 1972 predicted that world reserves of gold should be exhausted in 11 years, of mercury in 13 years, of silver in 16 years, of tin in 17 years, of oil in 31 years and so on. This alarming prediction has not yet come true for any of the substances mentioned.
This is due to the discovery of significant new deposits (especially of oil and coal), the application of new modern (zero-waste) technologies that save raw materials, and not least the recycling of raw materials.
Theoretically, there are many raw materials on Earth. For example, 79 chemical elements have been found in seawater. It is therefore in a sense a ‘liquid ore’. However, the technology to use it has not yet been developed. Currently, salt (12 million tonnes per year), deuterium and magnesium are extracted from seawater. Similarly, a large number of elements and compounds are found in the earth’s crust. Again, we know of no reliable way of extracting them.
Environmental problems
The extraction of minerals is associated with several environmental problems, not least with the processing of the extracted raw materials. Both surface and underground mining have a significant impact on the landscape. For example, mining can lead to the formation of surface holes, waste heaps and soil erosion, while opencast mining poses a potential risk of landslides. There are problems associated with contamination of water sources by heavy metals and sediments, as well as air pollution from blasting and transport activities, dust generation and mineral processing. The consequences of these problems are health, ecosystem disruption, and climate change.
As mineral extraction is important to modern lifestyles, it must be carried out in a way that is sensitive to the environment and reduces harmful impacts on land, water and air. To this end, modern technologies are being developed for extracting, processing and recycling these valuable natural resources.
