How do crystals form?

Rocks are mixtures of different minerals. All minerals are crystals, but not all crystals are minerals. These solid substances are found naturally in the ground. But do we know how they are formed?

How do crystals form?

Scientifically speaking, the term "crystal" refers to any solid that has an ordered chemical structure. This means that its parts are arranged in a precisely ordered pattern, like bricks in a wall. The "bricks" can be cubes or more complex shapes. I'm an Earth scientist and a teacher, so I spend a lot of time thinking about minerals. These are solid substances that are found naturally in the ground and can't be broken down further into different materials other than their constituent atoms. Rocks are mixtures of different minerals. All minerals are crystals, but not all crystals are minerals.

Most rock shops sell mineral crystals that occur in nature. One is pyrite, which is known as fool's gold because it looks like real gold. Some shops also feature showy, human-made crystals such as bismuth, a natural element that forms crystals when it is melted and cooled.

Why and how crystals form

Crystals grow when molecules that are alike get close to each other and stick together, forming chemical bonds that act like Velcro between atoms. Mineral crystals cannot just start forming spontaneously - they need special conditions and a nucleation site to grow on. A nucleation site can be a rough edge of rock or a speck of dust that a molecule bumps into and sticks to, starting the crystallization chain reaction. At or near the Earth's surface, many molecules are dissolved in water that flows through or over the ground. If there are enough molecules in the water that are alike, they will separate from the water as solids - a process called precipitation. If they have a nucleation site, they will stick to it and start to form crystals. Rock salt, which is actually a mineral called halite, grows this way. So does another mineral called travertine, which sometimes forms flat ledges in caves and around hot springs, where water causes chemical reactions between the rock and the air. You can make "salt stalactites" at home by growing salt crystals on a string. In this experiment, the string is the nucleation site. When you dissolve Epsom salts in water and lower a string into it, then leave it for several days, the water will slowly evaporate and leave the Epsom salts behind. As that happens, salt crystals precipitate out of the water and grow crystals on the string. Many places in the Earth's crust are hot enough for rocks to melt into magma. As that magma cools down, mineral crystals grow from it, just like water freezing into ice cubes. These mineral crystals form at much higher temperatures than salt or travertine precipitating out of water.

What crystals can tell scientists

Earth scientists can learn a lot from different types of crystals. For example, the presence of certain mineral crystals in rocks can reveal the rocks' age. This dating method is called geochronology - literally, measuring the age of materials from the Earth. One of the most valued mineral crystals for geochronologists is zircon, which is so durable that it quite literally stands the test of time. The oldest zircon ever found come from Australia and are about 4.3 billion years old - almost as old asour planet itself. Scientists use the chemical changes recorded within zircon as they grew as a reliable "clock" to figure out how old the rocks containing them are some crystals, including zircon, have growth rings, like the rings of a tree, that form when layers of molecules accumulate as the mineral grows. These rings can tell scientists all kinds of things about the environment in which they grew. For example, changesin pressure, temperature and magma composition can all result in growth rings. Sometimes mineral crystals grow as high pressure and temperatures within the Earth's crust change rocks from one type to another in a process called metamorphism. This process causes the elements and chemical bonds in the rock to rearrange themselves into new crystal structures. Lots of spectacular crystals grow in this way, including garnet, kyanite and staurolite.

Amazing forms

When a mineral precipitates from water or crystallizes from magma, the more space it has to grow, the bigger it can become. There is a cave in Mexico full of giant gypsum crystals, some of which are 40 feet (12 meters) long - the size of telephone poles. Especially showy mineral crystals are also valuable as gemstones for jewellery once they are cut into new shapes and polished. The highest price ever paid for a gemstone was $71.2 million for the CTF Pink Star diamond, which went up for auction in 2017 and sold in less than five minutes. (The author works at University of Montana.) THE CONVERSATION

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What is click chemistry?

The recent Nobel Chemistry Prize turned the spotlight on click chemistry that allows molecular building blocks to snap together quickly and efficiently.

Early in October, the Nobel Chemistry Prize was awarded to a trio of scientists-Carolyn R. Bertozzi, Morten Meldal, and K. Barry Sharpless-“for the development of click chemistry and bioorthogonal chemistry". While Sharpless and Meldal laid the foundation for a functional form of chemistry, Bertozzi took it to a new dimension by utilising it in living organisms.

Sharpless, who was awarded his second Nobel Prize in Chemistry, set the ball rolling around the year 2000 when he coined the concept of click chemistry. A simple and reliable form of chemistry, the reactions in click chemistry occur quickly and unwanted byproducts are avoided. Just like how children build with their blocks, click chemistry allows molecular building blocks to snap together quickly and efficiently.

Soon afterwards, Sharpless and Meldal independently arrived at a specific chemical reaction that uses copper ions as a catalyst. Now in widespread use, this reaction is seen as the crown jewel of click chemistry.

Many advantages

While the use of copper has many advantages, including that the reactions could be done at room temperature and could involve water, they can be toxic for the cells of living organisms.

Bertozzi took click chemistry to a new level by working on the foundations built by Sharpless and Meldal.

What Bertozzi did was to develop click reactions that work inside living organisms without disrupting the normal chemistry of the cell. She called this bioorthogonal chemistry- orthogonal meaning intersecting at right angles. While in click chemistry, the molecules clicked together in a straight flat line as in a seat belt, Bertozzi discovered more stable reactions by forcing the molecules at an angle.

Endless possibilities

Even though this is a very young field relatively, the Nobel Chemistry Prize was awarded to these scientists as this field has taken chemistry into an era of functionalism. While we are still scratching the surface, click chemistry and bioorthogonal chemistry are expected to bring great benefit to humanity. Click chemistry is already in use to create polymers that protect against heat and in varieties of glue in nano-chemistry. Other use cases include developing new targeted medicines. There is hope to create a targeted way to diagnose and treat cancer, including making chemotherapy have fewer severe side effects. The possibilities are literally endless at the moment.

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WHAT IS METHANE?

Methane is a hydrocarbon, which means that it is a compound made up of hydrogen and carbon atoms. It naturally occurs as an odourless, colourless, and tasteless gas. It is 25 times more dangerous Greenhouse gas than carbon dioxide. It can either be introduced into the environment by natural processes like the decomposition of the organic matter or by human activities like coal oil and natural gas extractions from the Earth, uncovered or poorly managed landfills and the burning of fossil fuels to name a few.

PRIMARY SOURCES OF METHANE EMISSIONS

Atmospheric methane concentrations have grown as a result of human activities related to agriculture, including rice cultivation and ruminant livestock; coal mining; oil and gas production and distribution; biomass burning; and municipal waste landfilling. Emissions are projected to continue to increase by 2030 unless immediate action is taken.

In agriculture, rapid and large scale implementation of improved livestock feeding strategies can reduce of 20% of global methane emissions by 2030, while full implementation of intermittent aeration of continually flooded rice paddies (known as alternate wetting and drying cultivation) could reduce emission from rice production by over 30%.

Emissions from coal mining and the oil and gas sector could be reduced by over 65% by preventing gas leakage during transmission and distribution, recovering and using gas at the production stage, and by pre-mine degasification and recovery of methane during coal mining.

METHANE IMPACTS

  • CLIMATE IMPACTS

Methane is generally considered second to carbon dioxide in its importance to climate change. The presence of methane in the atmosphere can also affect the abundance of other greenhouse gases, such as tropospheric ozone, water vapor and carbon dioxide.

Recent research suggests that the contribution of methane emissions to global warming is 25% higher than previous estimates.>

  • HEALTH IMPACTS

Methane is a key precursor gas of the harmful air pollutant, tropospheric ozone. Globally, increased methane emissions are responsible for half of the observed rise in tropospheric ozone levels.

While methane does not cause direct harm to human health or crop production, ozone is responsible for about 1 million premature respiratory deaths globally. Methane is responsible for about half of these deaths.

SOLUTIONS

The relatively short atmospheric lifetime of methane, combined with its strong warming potential, means that targeted strategies to reduce emissions can provide climate and health benefits within a few decades.

The Coalition supports implementation of control measures that, if globally implemented by 2030, could reduce global methane emissions by as much as 40%. Several of these emission reductions could be achieved with net savings, providing quick benefits for the climate as well as public health and agricultural yields.

Credit : Climate & clean air coalition   

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WHAT ARE HYDROFLUOROCARBONS?

Hydrofluorocarbons (HFCs) are a group of industrial chemicals primarily used for cooling and refrigeration. HFCs were developed to replace stratospheric ozone-depleting substances that are currently being phased out under the Montreal Protocol on Substances that Deplete the Ozone Layer.

Many HFCs are very powerful greenhouse gases and a substantial number are short-lived climate pollutants with a lifetime of between 15 and 29 years in the atmosphere.

Though HFCs currently represent around 1% of total greenhouse gases, their impact on global warming can be hundreds to thousands of times greater than that of carbon dioxide per unit of mass. Assuming no new regulation, HFC consumption is projected to double by 2020, and emissions could contribute substantially to radiative forcing in the atmosphere by the middle of the century.

The Kigali Amendment to phase down HFCs under the Montreal Protocol entered into force in 2019. Under the amendment, countries commit to cut the production and consumption of HFCs by more than 80% over the next 30 years to avoid more than 70 billion metric tons of carbon dioxide equivalent emissions by 2050 -- and up to 0.5° C warming by the end of the century. Solutions are available to replace high-global warming potential HFCs in many sectors and reduce emissions.

HFCs CLIMATE IMPACTS

HFCs are potent greenhouse gases that can be hundreds to thousands of times more potent than carbon dioxide (CO2) in contributing to climate change per unit of mass. A recent study concluded that replacing high-GWP HFCs with low-GWP alternatives could avoid 0.1°C of warming by 2050. Fast action under the Montreal Protocol could limit the growth of HFCs and avoid up to 0.5°C of warming by 2100.

SOLUTIONS

HFCs can be most effectively controlled through a phase down of their production and consumption.

In addition to the direct climate benefits from HFC mitigation, a global HFC phase down could also provide indirect benefits through improvements in the energy efficiency of the refrigerators, air conditioners, and other products and equipment that use these chemicals. These efficiency gains could also lead to reduced emissions of CO2 and other air pollutants.

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WHAT ARE GREENHOUSE GASES?

Atmospheric gases that absorb infrared radiation and trap heat are called greenhouse gases. These gases let sunlight pass through the atmosphere and prevent the heat from the sunlight from leaving the atmosphere - just like a greenhouse. The main greenhouse gases are water vapour, methane, carbon dioxide, ozone, nitrous oxide and chlorofluorocarbons. While some amount of greenhouse gases in the atmosphere is required to keep the earth habitable, too much, induced by human activity is bad.

Greenhouse gases are gases that can trap heat. They get their name from greenhouses. A greenhouse is full of windows that let in sunlight. That sunlight creates warmth. The big trick of a greenhouse is that it doesn’t let that warmth escape.

That’s exactly how greenhouse gases act. They let sunlight pass through the atmosphere, but they prevent the heat that the sunlight brings from leaving the atmosphere. Overall, greenhouse gases are a good thing. Without them, our planet would be too cold, and life as we know it would not exist. But there can be too much of a good thing. Scientists are worried that human activities are adding too much of these gases to the atmosphere.

Human activities since the beginning of the Industrial Revolution (around 1750) have increased the atmospheric concentration of carbon dioxide by almost 50%, from 280 ppm in 1750 to 419 ppm in 2021. The last time the atmospheric concentration of carbon dioxide was this high was over 3 million years ago. This increase has occurred despite the absorption of more than half of the emissions by various natural carbon sinks in the carbon cycle.

At current greenhouse gas emission rates, temperatures could increase by 2 °C (3.6 °F), which the United Nations' Intergovernmental Panel on Climate Change (IPCC) says is the upper limit to avoid "dangerous" levels, by 2050. The vast majority of anthropogenic carbon dioxide emissions come from combustion of fossil fuels, principally coal, petroleum (including oil) and natural gas, with additional contributions from cement manufacturing, fertilizer production, deforestation and other changes in land use.

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WHAT ARE FLUORINATED GASES?

Fluorinated gases or F-gases are a family of human-made fluorine-based gases. They are powerful greenhouse gases that trap heat and hasten global warming. Though they find wide applications in households and industries, many countries such as the UK have imposed regulations on their use as a step towards combating the climate crisis.

There are three main types of F-gases:

  • hydrofluorocarbons (HFCs)
  • perfluorocarbons (PFCs)
  • sulphur hexafluoride (SF6).

Main uses of F-gases F-gases are used in a number of ways:

  • Stationary refrigeration, air conditioning and heat pump (RAC) equipment are some of the largest sources of F-gas emissions.
  • Some stationary fire protection systems and portable fire extinguishers currently use HFCs.
  • Mobile air conditioning in cars and light vans currently uses HFCs. Other air-conditioned and refrigerated transport also uses F-gases.
  • Solvents containing F-gases are used to clean components, eg in the electronics and aerospace industries. 
  • F-gases have many specialist uses such as in the production of magnesium, different types of foam and high voltage switchgear.

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WHAT IS CHLOROFLUOROCARBONS?

Any of several organic compounds composed of carbon, fluorine, and chlorine, chlorofluorocarbons (CFCS) are non-toxic non-flammable chemicals. If it contains hydrogen in place of one of the chlorines, they are called hydrochlorofluorocarbons (HCFCS) Originally developed as refrigerants in the 1930s. CFCs gained commercial and industrial value as they found use in the manufacture of aerosol sprays, solvents and foam-blowing agents. CFCS, however, were eventually discovered to pose an environmental threat at a serious: level as they contribute to the depletion of the ozone layer and hence are being phased out throughout the world.

What are the applications of CFC?

Chlorofluorocarbons are used in a variety of applications because of their low toxicity, reactivity and flammability. Every permutation of fluorine, chlorine and hydrogen-based on methane and ethane has been examined and most have been commercialized.

Furthermore, many examples are known for higher numbers of carbon as well as related compounds containing bromine. Uses include refrigerants, blowing agents, propellants in medicinal applications and degreasing solvents.

How do CFCs impact the environment?

However, the atmospheric impacts of CFCs are not limited to their role as ozone-depleting chemicals. Infrared absorption bands prevent heat at that wavelength from escaping the earth’s atmosphere. CFCs have their strongest absorption bands from C-F and C-Cl bonds in the spectral region of 7.8–15.3 µm—referred to as “atmospheric window” due to the relative transparency of the atmosphere within this region.

The strength of CFC absorption bands and the unique susceptibility of the atmosphere at wavelengths where CFCs (indeed all covalent fluorine compounds) absorb creates a “super” greenhouse gas (GHG) effect from CFCs and other unreactive fluorine-containing gases such as perfluorocarbons, HFCs, HCFCs, bromofluorocarbons.

Use of certain chloroalkanes as solvents for large-scale application, such as dry cleaning, have been phased out, for example, by the IPPC directive on greenhouse gases in 1994 and by the volatile organic compounds (VOC) directive of the European Union in 1997. Permitted chlorofluoro alkane uses are medicinal only.

According to scientific communities, the hole in the ozone layer has begun to recover as a result of CFC bans. India is one of the few countries that are pioneers in the use of non-Ozone Depleting technologies and have a low Global Warming Potential (GWP).

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WHAT IS WEATHERING CAUSED BY SALT CRYSTALS CALLED?

Haloclasty is a type of physical weathering caused by the growth of salt crystals. The process is first started when saline water seeps into cracks and evaporates depositing salt crystals. When the rocks are then heated, the crystals will expand putting pressure on the surrounding rock which will over time splinter the stone into fragments.

Salt crystallization may also take place when solutions decompose rocks (for example, limestone and chalk) to form salt solutions of sodium sulfate or sodium carbonate, from which water evaporates to form their respective salt crystals.

The salts which have proved most effective in disintegrating rocks are sodium sulfate, magnesium sulfate, and calcium chloride. Some of these salts can expand up to three times or more in volume.

It is normally associated with arid climates where strong heating causes strong evaporation and therefore salt crystallization. It is also common along coasts. An example of salt weathering can be seen in the honeycombed stones in sea walls.

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What is Meteorology?

No, it isn't the study of meteors, although it does involve the study of other sorts of objects that fall from the sky. Meteorology is, by definition, the study of Earth's atmosphere. The root of meteor is a variation on the Greek meteoron, which is a term dealing with any objects that originate in the sky.

Meteorology is an extremely interdisciplinary science, drawing on the laws of physics and chemistry (among others) to aid in our understanding of Earth's atmosphere, its processes, and its structure. It is a study that dates to ancient times, when ancient civilizations made observations and kept records of weather conditions, both for agricultural purposes and out of a general curiosity about the world around them.

Over the centuries, the atmosphere has been studied for a variety of reasons, including agricultural knowledge, military defense and planning, and developing better warnings for severe weather systems like tornadoes and hurricanes. Technological advances, such as the development of scientific computing and an increase in the total number of meteorological observations being taken daily across the globe, have allowed for better forecasts (or at least the meteorological community likes to think they are better forecasts) and a much better overall understanding of our atmosphere.

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WHO STUDIES ROCKS AND MINERALS?

A geologist is a scientist who studies the solid, liquid, and gaseous matter that constitutes Earth and other terrestrial planets, as well as the processes that shape them. Geologists usually study geology, although backgrounds in physics, chemistry, biology, and other sciences are also useful. Field research (field work) is an important component of geology, although many subdisciplines incorporate laboratory and digitalised work.

Geologists work in the energy and mining sectors searching for natural resources such as petroleum, natural gas, precious and base metals. They are also in the forefront of preventing and mitigating damage from natural hazards and disasters such as earthquakes, volcanoes, tsunamis and landslides. Their studies are used to warn the general public of the occurrence of these events. Geologists are also important contributors to climate change discussions.

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WHAT IS FLUORITE?

Fluorite is a very popular mineral, and it naturally occurs in all colors of the spectrum. It is one of the most varied colored minerals in the mineral kingdom, and the colors may be very intense and almost electric. Pure Fluorite is colorless; the color variations are caused by various impurities. Some colors are deeply colored, and are especially pretty in large well-formed crystals, which Fluorite often forms. Sometimes coloring is caused by hydrocarbons, which can be removed from a specimen by heating. Some dealers may apply oil treatment upon amateur Fluorite specimens to enhance luster.

Fluorite has interesting cleavage habits. The perfect cleavage parallel to the octahedral faces can sometimes be peeled off to smooth out a crystal into a perfect octahedron. Many crystals, especially larger ones, have their edges or sections chipped off because of the cleavage.

Fluorite is one of the more famous fluorescent minerals. Many specimens strongly fluoresce, in a great variation of color. In fact, the word "fluorescent" is derived from the mineral Fluorite. The name of the element fluorine is also derived from Fluorite, as Fluorite is by far the most common and well-known fluorine mineral.

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WHY ARE AMETHYSTS PURPLE?

The color in amethyst comes from color centers in the quartz. These are created when trace amounts of iron are irradiated ( from the natural radiation in the rocks).

The purple color in ghost town glass comes from small amounts of manganese in the glass when it has been exposed to ultraviolet light. The manganese was used as a clarifying ingredient in glass from 1860 to 1915. Prior to that, lead was used, and subsequently, selenium is used.

Quartz will commonly contain trace amounts of iron ( in the range of 10's to 100's parts per million of iron). Some of this iron sits in sites normally occupied by silicon and some is interstitial (in sites where there is normally not an atom). The iron is usually in the +3 valence state.

Gamma ray radiation can knock an electron from an iron lattice site and deposit the electron in an interstitial iron. This +4 iron absorbs certain wavelengths (357 and 545 nanometers) of light causing the amethyst color. You need to have quartz that contains the right amounts of iron and then is subjected to enough natural radiation to cause the color centers to form.

The color of amethyst has been demonstrated to result from substitution by irradiation of trivalent iron (Fe+3) for silicon in the structure, in the presence of trace elements of large ionic radius, and, to a certain extent, the amethyst color can naturally result from displacement of transition elements even if the iron concentration is low.

Amethyst occurs in primary hues from a light pinkish violet to a deep purple. Amethyst may exhibit one or both secondary hues, red and blue. The best varieties of amethyst can be found in Siberia, Sri Lanka, Brazil and the far East. The ideal grade is called "Deep Siberian" and has a primary purple hue of around 75–80%, with 15–20% blue and (depending on the light source) red secondary hues.

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WHAT ARE VALUABLE MINERALS?

Valuable minerals are either metal or rock that can be processed and converted for economic purposes. Gemstones such as diamonds, rubies, sapphires and emeralds are valuable minerals. Gold and silver are also precious. Palladium is considered more precious than gold and it is very valuable to automotive industries.

Diamond

Diamond is commercially the most popular mineral because of its eminent role in the world of jewelry trading.

 Rubies

Rubies are considered to be the most expensive gemstones in the world. They get their alluring red color from the presence of chromium. The largest supply of this mineral was harvested in Burma, which is known as the Mecca for rubies.

Gold

Many people think gold is the most valuable and most expensive mineral in the world, but this is a common misconception because there are other minerals that are far more worthy than gold. Still, it is a highly valued, expensive mineral.

Rhodium

Because of its rarity and industrial application, this silver-white noble metal is the world’s most expensive mineral. Rhodium became popular as a result of its highly valued catalytic application in the automotive industry. The largest supply of this mineral was found in 2009 in South Africa and Russia.

Lithium

This mineral which is commonly known as a crucial ingredient in the production of rechargeable batteries was first discovered in 1817 in Stockholm by the Swedish chemist Johan August Arfvedson. Lithium is a highly valued mineral which represents a billion dollar industry. The largest supplies of this mineral are found in Afghanistan.

Blue Garnet

Garnets can be found in various colors like brown, green, orange, pink, purple, red and yellow. Among all these colors the blue garnet is the only one with a considerably high value. This mineral was first discovered in the 1990s in Madagascar, and since then it has been mined in Russia, Turkey and the United States.

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WHY ARE DIAMONDS EXTRAORDINARY?

Very hard, very rare and very old, diamonds are essentially carbon that has been transformed under great pressure deep inside Earth. It is usually volcanic activity that brings them near the surface again after billions of years and makes mining possible. Diamonds are the hardest natural substance ever found.

  1. The ancient Romans and Greeks believed that diamonds were tears cried by the gods or splinters from falling stars, and Romans believed that Cupid’s arrows were tipped with diamonds (perhaps the earliest association between diamonds and romantic love).
  2. Diamonds are nearly as old as the earth and take billions of years to form deep in the pit of the earth. Very few diamonds survive the trip from the depths of the earth to the crust where they can be mined. No two diamonds are the same and carry their own unique properties such as internal inclusions and color. 
  3. Diamonds form about 100 miles below ground and have been carried to the earth’s surface by deep volcanic eruptions.
  4. Diamonds are made of a single element—they are nearly 100% carbon. Under the extreme heat and pressure far below the earth’s surface, the carbon atoms bond in a unique way that results in diamonds’ beautiful and rare crystalline structure.
  5. The word diamond derives from the Greek word “adamas,” which means invincible or indestructible.
  6. Diamonds are the hardest natural substance on earth ranking a 10 on the Mohs Scale of Hardness. The only thing that can scratch a diamond’s surface is another diamond.
  7. Diamonds have been valued and coveted for thousands of years by the likes of royalty and mythical beings. There is evidence that diamonds were being collected and traded in India as early as the fourth century BC. In the first century AD, the Roman naturalist Pliny is quoted as having said, “Diamond is the most valuable, not only of precious stones, but of all things in this world.”
  8. Ancient Hindus used diamonds in the eyes of devotional statues and believed that a diamond could protect its wearer from danger.
  9. Many ancient cultures believed that diamonds gave the wearer strength and courage during battle, and some kings wore diamonds on their armor as they rode into battle.
  10. During the Middle Ages diamonds were thought to have healing properties able to cure ailments ranging from fatigue to mental illness. 

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WHAT ARE MINERALS?

Minerals are natural chemicals from which Earth's crust is formed. There are around 2000 individual minerals, each with a unique colour and shape. A few are powdery or resinous, but most are crystals. Some minerals, such as gold and silver, are pure chemical elements, but the majority are compounds, of which silicates are most common.

The earth is composed of mineral elements, either alone or in a myriad of combinations called compounds. A mineral is composed of a single element or compound. By definition, a mineral is a naturally occurring inorganic substance with a definite chemical composition and ordered atomic structure.

  • Table salt is a mineral called sodium chloride. Its ordered structure is apparent because it occurs in crystals shaped like small cubes.
  • Another common mineral is quartz, or silicon dioxide. Its crystals have a specific hexagonal shape. Coal is a mineral composed entirely of carbon, originally trapped by living organisms through the process of photosynthesis.
  • The carbon in coal is therefore of organic origin which leads some authorities to object to the definition of a mineral as an inorganic substance.
  • Limestone is a rock composed of a single mineral calcium carbonate. On the basis of their origin on earth rocks may be divided into three primary categories: igneous, sedimentary and metamorphic.

Minerals have been broadly classified into two classes, primary minerals and secondary minerals. Minerals which were formed by igneous process that is from the cooling down of the molten materials called magma, have been put in the primary category, while those formed by other processes have been put in the secondary category. Primary minerals which occur in the sand fractions of the soil had not undergone any change.

Other primary minerals had been altered to form the secondary minerals for example, the primary mineral mica had been altered to form the secondary mineral illite. Some other primary minerals for example, olivine, anorthite, hornblende etc., had been completely decomposed; the decomposition products recombined together to form the secondary minerals.

Minerals may be identified by their crystal structure, physical properties and chemical composition.

Like vitamins, minerals help your body grow, evolve and remain healthy. The body uses minerals to perform many functions — from building strong bones to nerve impulse transmission. Some minerals also create hormones or hold a regular heartbeat.

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