My Science School

As air expands, it becomes cooler. Air in the mountains, where the altitude (height above sea level) is higher, is under less pressure than air at lower altitudes because it is not being so compressed by the air above it. As a result, it expands and makes mountainous areas cold.

When air expands, it has to push the surrounding air out of its way, which means that it expends part of its energy to do the pushing. As a result, the expanding air cools. When air contracts, it gets pushed into a smaller space by the air around it, which means that energy is put into it, which heats it up. Eventually, the expanding or contracting air will reach the same temperature and pressure as the air surrounding it, and the heating and cooling will stop. Air at higher altitude is under less pressure than air at lower altitude because there is less weight of air above it, so it expands (and cools), while air at lower altitude is under more pressure so it contracts (and heats up).

Air in our atmosphere moves up and down as part of the weather: the sun heats up the ground (which absorbs more light than air and is thus warmer than the air), and the air in contact with the ground heats up, and expands (and then cools). Elsewhere, cooler higher-altitude air sinks, is compressed as it descends, and gets heated as this occurs. This process is called "convection", and it is responsible for nearly all of our weather.

Credit: UCSB ScienceLine

Picture credit: Google

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.

Credit: Wikipedia

Picture credit: Google

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.

Credit: Minerals.net

Picture credit: Google

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.

Credit: Geology In

Picture credit: Google

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.

Credit: Mining Greece

Picture credit: Vector Stock

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. 

Credit: Brilliant Earth

Picture credit: Google

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.

Credit: Byju’s

Picture credit: Geology In

Crystals are glassy-looking, brittle solids that form shapes with sharp corners and flat sides. Natural crystals form when a liquid cools and hardens, and the molecules in the liquid cluster in a particular pattern - a pyramid, cube, etc. Rare and beautiful crystals such as rubies and emeralds are valued as gems. Many are termed 'precious'. They are rare because they only form naturally under very special conditions - usually deep within volcanic rocks.

Crystals are pure substances whose atoms, molecules, or ions are arranged in an ordered pattern, where they extend in all three spatial dimensions. A gem can be a crystal, while a crystal cannot be called as a gem.

Gemstone and Crystals are both used in various applications in today’s world. While gemstones are primarily used in jewelry and decoration pieces, crystals can be used in various applications such as healing, jewelry, vases, scientific purposes, etc.

Gemstones are rare pieces of minerals that are found in the ground, which are then cut and polished to be used in jewelry and other decorative pieces. Not all gems are minerals, such as lapis lazuli, a rock, and amber or jet, which are organic materials. A gemstone can also be known as precious or semi-precious stones. Precious stones include diamonds, emerald, ruby and sapphire, while the rest are qualified as semi-precious stones. Gemstones are classified by their color, translucency and hardness. Gems can also come with mineral bases like diamonds or rubies and with organic bases like amber. Today, geologists use the chemical composition of a gemstone to classify it into groups, species and varieties. The price of the gemstones depends on the rarity, color, composition, hardness and cut.

Crystals are pure substances whose atoms, molecules, or ions are arranged in an ordered pattern, where they extend in all three spatial dimensions. The process of crystal formation via mechanisms of crystal growth is called crystallization or solidification. Not all crystals need to be in solid formation, where water freezing also begins with small ice crystals that grow. Crystal symmetry requires that the unit cells stack perfectly with no gaps. Crystals are classified as Hexagonal, cubic, orthorhombic, tetragonal, rhombohedral, and monoclinic shapes. Crystals are light in color and are mostly translucent. The color of crystal is determined by the light passing through it.  Crystals are less expensive compared to gemstones. Salt and snowflakes are the most common types of crystals that are encountered.

Credit: Difference Between

Picture credit: Google

When silicon and oxygen, the two most common chemical elements on Earth, combine with a metal, they forma silicate. There are over 500 silicates that exist, quartz is one.

Silicate mineral, any of a large group of silicon-oxygen compounds that are widely distributed throughout much of the solar system.

The silicates make up about 95 percent of Earth’s crust and upper mantle, occurring as the major constituents of most igneous rocks and in appreciable quantities in sedimentary and metamorphic varieties as well. They also are important constituents of lunar samples, meteorites, and most asteroids. In addition, planetary probes have detected their occurrence on the surfaces of Mercury, Venus, and Mars. Of the approximately 600 known silicate minerals, only a few dozen—a group that includes the feldspars, amphiboles, pyroxenes, micas, olivines, feldspathoids, and zeolites—are significant in rock formation.

Credit: Britannica

Picture credit: Google

Imagine walking on a planet that is full of diamond. Dubbed 55 Cancri e, an exoplanet twice the size of Earth, is composed of carbon mostly in the form of graphite and diamond. At least a third of the planet's mass is likely diamond as a result of the temperatures and pressures in the planet's interior. Further observations are necessary to confirm the nature of the planet. It orbits a Sun-like hot star called 55 Cancri A. Planets like this are vastly different from our Earth, which has relatively less carbon.

Astronomers discovered the planet in 2004 after looking at the spectrum of its parent star, 55 Cancri A, one of two stars in a binary system about 40 light-years from Earth in the constellation Cancer. There are at least four other planets in the same system, mostly discovered before 55 Cancri e. The team (led by the University of Texas at Austin's Barbara McArthur) discovered subtle tugs on the parent star that could be explained by the presence of yet another planet. While the planet's existence was challenged by a second research team in 2005, a separate team in 2006 confirmed it. 

Astronomers initially thought 55 Cancri e (abbreviated 55 Cnc e) had an orbital period of 2.8 days, but measurements in 2011 showed that the planet is much closer to its parent star. Observations with Canada's MOST (Microvariability & Oscillations of STars) space telescope demonstrated an orbital period of less than 18 hours. Researchers estimated the surface temperature of 55 Cancri e could be as high as 4,892 F (2,700 C). 

Follow-up observations with the Spitzer Space Telescope in 2012 showed that 55 Cancri e is much weirder than anticipated. While original estimates said the planet was dense and rocky, Spitzer suggested the planet includes a healthy proportion of light elements and compounds (such as water). However, the planet's high surface temperatures contribute to a "supercritical" fluid state, the researchers said, meaning that the gases are in a liquid-like state. 

Credit : Space.com

Picture Credit : Google 

 

Many types of stones are available such as basalt, marble, limestone, sandstone, quartzite, travertine, slate, gneiss, laterite, and granite, which can be used as construction materials. The stones used for building construction should be hard, durable, tough, and should be free from weathered soft patches of material, cracks, and other defects that are responsible for the reduction of strength and durability. Stones for construction purposes are obtained by quarrying from massive solid rocks.

Each type of stone lends itself to various construction applications based on its properties. For instance, certain types like basalt and granite have superior characteristics like high compressive strength and durability and hence employed in major construction works. However, there are stones that their characteristic makes them suitable for minor construction works, for example, gneiss. So, stones are used as a building material and also for decorative purposes.

TYPES OF BUILDING STONES

Some of the common building stones which are used for different purposes in India are as follows:

GRANITE

It is a deep-seated igneous rock, which is hard, durable and available in various colours. It has a high value of crushing strength and is capable of bearing high weathering.

BASALT AND TRAP

They are originated from igneous rocks in the absence of pressure by the rapid cooling of the magma.

TRAP STONE

They have the same uses as granite. Deccan trap is a popular stone of this group in South India.

LIMESTONE

Limestone is used for flooring, roofing, pavements and as a base material for cement. It is found in Maharashtra, Andhra Pradesh, Punjab, Himachal Pradesh and Tamil Nadu.

SANDSTONE

This stone is another form of sedimentary rock formed by the action of mechanical sediments. It has a sandy structure which is low in strength and easy to dress.

Credit: cmpstone.com

Picture credit: Google

A mixture of different-sized pebbles cemented by sand, formed in river channels over thousands of years. It looks a bit like a Christmas pudding.

Puddingstone is a nonscientific name for a conglomerate in which subrounded to rounded pebbles occur in a matrix of sharply contrasting color.

The name "puddingstone" was first used in Great Britain where the rocks were said to "look like a plum pudding". A well-known example is the Hertfordshire Puddingstone, from the lower Eocene of the London Basin. It consists of colorful flint pebbles in a white to brown silicate matrix. It is a rock found at many locations in Hertfordshire County, England.

Puddingstones immediately catch the eye of the geologist and the eyes of people who otherwise have no special interest in rocks. People have an immediate interest in the rocks and carry them home from beaches, streams, and wherever they are found.

Many particularly nice specimens find a place on desks, bookshelves, window sills and other locations where they will be seen by and delight even more people. Their popularity greatly exceeds their abundance.

Credit: Geology.com

Picture credit: Google

Limestone is a sedimentary rock composed mainly of the mineral calcite, which is a crystalline form of Calcium Carbonate (CaCO3). Limestone often contains variable amounts of silica in the form of Jasper or Flint, as well as amounts of clay, silt, and sand as disseminations, nodules, or layers within the rock unit. The main source of this calcite in limestone is speleothems such as stalagmites and stalactites. The secondary source of calcite is the shells of sea animals and corals.

Limestone makes up about 10 percent of the total volume of all sedimentary rocks. Most Limestone starts as the floor of shallow tropical seas and can be seen in parts of the tropics that are only 30 to 40 years old. The stone has the unique property of retrograde solubility, meaning that the stone is less soluble in water as the temperature increases.

Limestone is also classified as a young marble formed from the consolidation of seashells and sediment. Shells of sea animals form grains in limestone that promotes the growth of cement crystals around themselves.

Limestone is a popular building material because of its availability and the relative ease with which it can be worked with and cut. The stone can have a very diverse chemical composition, which can result in a variety of different colours of limestone or even within a single cut of the stone.

Credit: Banas stones

Picture credit: Wikipedia

About 300 million years ago, in the Carboniferous period, there were huge tropical swamps filled with giant tree-like ferns. As the remains of the plants were buried and compacted in these huge, warm Swamps, they formed peat. As they sank deeper, heat and pressure changed the peat into brown coal. Further pressure changed it to black bituminous coal.

Coal swamps are the classical terrestrial (land-based) ecosystems of the Carboniferous and Permian periods. They are forests that grew during the Palaeozoic Era (encompassing the Carboniferous and Permian) in which the volume of plant biomass dying and being deposited in the ground was greater than the volume of clastic (grains of pre-existing rock) material, resulting in a build-up of peat. This was subsequently buried, and eventually turned into coal over geological time. These swamps gave rise to most of the major, industrial-grade coal reserves that are mined today. The palaeontology of these coal-forming ecosystems is well known from the Carboniferous rocks of Euramerica (modern day Europe and North America), owing to the history of coal exploitation in these regions. However, extensive swamp areas that produced thick coal reserves have also formed at other times in the Earth’s history, most notably in the Permian. During the Early Permian, the coal swamps of Euramerica continued to flourish in Cathaysia (the tectonic blocks that formed modern day China), and throughout the Permian, coal swamps dominated by seed plants called glossopterids were found on the Southern Hemisphere supercontinent Gondwana (formed from modern day India, Australia, Antarctica, Africa, Madagascar and South America). The coal swamps of the Carboniferous and Early Permian formed primarily in tropical regions, whereas the Gondwanan coal swamps of the later Permian formed in higher-latitude temperate regions. Coal forests developed primarily in lowland areas such as river deltas, but there is a bias in the plant fossil record because fossilization is most likely to occur in these waterlogged habitats, meaning that fossils of drier, upland plant communities are much less common, so little is known of the plants that grew there.

Credit: palaeontologyonline.com

Picture credit: Google

No. Although coal is sometimes called an organic rock, it is not a proper rock as rocks are inorganic (lifeless). Coal is a fossil fuel - like oil and gas- that formed over millions of years from the remains of once-living matter.

Coal is the largest source of energy for generating electricity in the world, and the most abundant fossil fuel in the United States.

Fossil fuels are formed from the remains of ancient organisms. Because coal takes millions of years to develop and there is a limited amount of it, it is a nonrenewable resource.

The conditions that would eventually create coal began to develop about 300 million years ago, during the Carboniferous period. During this time, the Earth was covered in wide, shallow seas and dense forests. The seas occasionally flooded the forested areas, trapping plants and algae at the bottom of a swampy wetland. Over time, the plants (mostly mosses) and algae were buried and compressed under the weight of overlying mud and vegetation.

As the plant debris sifted deeper under Earth’s surface, it encountered increased temperatures and higher pressure. Mud and acidic water prevented the plant matter from coming into contact with oxygen. Due to this, the plant matter decomposed at a very slow rate and retained most of its carbon (source of energy).

These areas of buried plant matter are called peat bogs. Peat bogs store massive amounts of carbon many meters underground. Peat itself can be burned for fuel, and is a major source of heat energy in countries such as Scotland, Ireland, and Russia.

Credit: Society

Picture credit: Google