The history of Geology is as ancient as the life on Earth, but it has been a matter of interest to humans only back in the 4th century. It was after Aristotle observed the evolution of rocks and minerals, the scientists and philosophers started to learn and mine certain crust around the 5th century. Geology, as a separate branch of science, was developed in the late 17th century. The geologists from various academies started to investigate every layer of earth and stop at every stone to find the fossils embedded within the Earth.
Rock Art is the term used by a number of historians over years. They are images embossed, carved or furrowed on a rock surface and are used to convey messages before writing has originated. They are simply the markings on a natural stone, according to archaeology, and this “rock art” is divided into the sub-disciplines in the late 19th century, like petroglyphs and pictographs. Petroglyphs are the carvings reflecting the Stone Age, while Pictographs are drawing or paintings on rocks.
Deriving from pre-historic times, these stone pecking is created by the ancestors of Pueblo people who lived in the Rhio Grande valley before A.D.500. These powerful cultural symbols reflect the tribal society and their ceremonies. Each carving relates to a known or unknown context which is extremely important, orienting the sphere or scenery. Some petroglyphs have meanings that are known only to its master while others are contemporary designs of religious existence, sceneries or any area and are honoured for its origin.
A pictograph, by the name itself, expresses the prehistoric abstracts in paintings or images on a rock. They are carefully arranged to convey messages, for example, paintings of animal hunting or wild animals of that era. These served as the pioneer for information about the ancient civilization and their habituates. The art forms are engraved in almost every cave that can be interpreted as the primitive symbols of hunting.
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Mineraloids are not true minerals as they lack crystalline structures. They do not have a perfect formula and are inorganic naturally forming solid without the cleavage property. Abmer, Jet, Obsidian, Pearl and Pumice are some of the good examples of mineraloids. They are formed after the rapid solidification from a melt, where the constituents fail to develop an ordered atomic structure. They are formed by volcanic traits, Obsidian, for example is a randomly formed network of volcanic glass.
Mineraloids can be even from the galaxy of stars. Tektites and Moldavites are some among the outer space materials to the earth formed as a result of an asteroid or comet. They collide with Earth at very high velocity generating a large mass of energy. The explosion melts the rock into a stream of molten material, extending the molten to wide landscapes. As the temperature falls, it solidifies quickly and gives out amorphous pieces.
The Libyan Desert glass is believed to be yellow, is originated from a desert environment due to the lighting. Enormous spaces of deserts were flash melted with lightning strikes and they rapidly congeal as amorphous silica producing glassy textures. The Moldavites are also from the flash-heat phenomena and are found in the Eastern Europe. They amuse the geo-travellers and collectors with its beautiful green colour, and the clear stones can be modified as a gem.
Organic mineraloids like Amber, found on sedimentary rock clusters, is actually the fossil plant resin. Another gem is the Jet, which is the rare black coal has a polished bright texture and are often cut into gemstones. The geologists are still searching for the evidence for Radiolarians and diatoms to be considered under mineraloids or not. The teeny-weeny creatures having thin amorphous shells sinks under the grounds cumulates to form sediments called ooze which eventually results in these organic solids.
Mineraloid environments are created beneath the earth’s surface where temperature and pressure are low. Materials like chrysocolla, limonite and opal freeze from gels and moulds to form minerals at favourable heat and temperature zones in the long run. Water and Mercury are also categorised as a natural inorganic substance which on modification changes to water ice and supercooled mercury.
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The fossils have been a fantasy for almost every one of us at some ages of our lives. The Hollywood movies and the animations tremendously influenced many of us to seek more about the origin and identity of fossils. The fossils of Dinosaurs may be the first thing that arises in our minds when we hear of fossils. But it’s a truth that outside the walls of a museum or university, there is astounding collection of these remains at the beaches or coasts of England.
Before the journey to fossils, it is advisable to have a journal research regarding the places to visit. The Fossil masses can be seen at the England beaches like the Jurassic Coast in East Devon and Dorset, the Isle of Wight and the east Coast of Yorkshire. The Charmouth at Dorset has cliffs of Jurassic ocean floors where life existed over 200million years ago. When the cliffs crashed into the sea, the waves swept them away leaving behind the fossils on to the shores. There are also skeletons of giant reptiles and other endangered species. The skeleton of Scelidosaurus, the herbivorous species among dinosaurs, was discovered in December 2000. They inhabit the tropical islands around Charmouth.
The favourable time for fossil search is from April through November. Winter keeps the sea rough, giving a more clear vision of fossils. The dangerous tides can be a challenge and safety measures are to be followed.
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In earlier days, many geologists compared the hardness of a mineral by seeing which mineral can scratch others visibly and this lacks precision and accuracy. Hence, The Mohs scale was invented to measure the scratch resisting property of various minerals. Introduced by the German mineralogist, Friedrich Mohs in 1812, it measures the ability of one natural mineral to scrape another visibly.
Many minerals of pure and hard in nature were sampled and it was found that diamonds are the hardest naturally occurring mineral known so far. Scratching a mineral to measure on the scale creates non-elastic disorders visible to the naked eye. Minerals that are on the lower side of Mohs scale produce these distortions on materials and they have a higher Mohs number. If both the samples are of equal hardness, they will be no effect for the scrape, or might be difficult to determine the scratch.
The procedure is as simple as it states. During the test, place the specimen to detect hardness on the table and hold it tightly in one hand. The reference specimen is kept against the unmarked surface of the sample. With a force, press the reference against the sample and give it a short drag move. Avoid injuries with sharp edges by placing away from your body. Check the blemish if they produced after dusting the residue of mineral powder. Use a hardness pick to get enhance accuracy. They are sharp metal picks, used to create a scrape easily if they are harder than the specimen being tested or leave a mere streak of metal if they are softer.
Hardness test is done as a mode of mineral identification easily when sophisticated techniques are unavailable. The suitability of the material to be used is determined in industries during the manufacture of products. It also helps to confirm that the materials that undergo wear and tear during the manufacturing withstand the pressure.
Ever wondered the science behind those glow in the dark effects? Pyrotechnics are nothing but the art of creating the firework display. The Chinese invented fireworks around 960AD which are now the part and prestige of every celebration across the world. The gears behind the brilliant colours and designs are a fusion of chemistry, physics and mathematics. People all over the world enjoy the tremendous booms of crackers, however, for science, these are the mass of powerful chemicals and fuels mounted together and calibrated to produce specific designs and colours.
The aerial magic of colours in the sky is the result of the explosion of a firework shell, with packed stars that are propelled to the air. The shell consists of gunpowder which is a mixture of charcoal, sulphur and potassium, in a paper tube with fuse installed to spark the tube. The outer cylinder is made of plastic or metal, where the gunpowder is filled with bottom of stars. The stars, in different shapes like cubes, spheres, cylindrical are nothing but the compounds that create colour and effects. The multiple fuses which ignite upon charge control the delay in time of the explosion.
The chemical makeup has a specific recipe for each colour with the deliberate addition of metallic compounds during the manufacture of stars. The pre-defined sculpting and mixing of stars emits specific colours and explodes to the sky with vibrant colours. The intensity of burst charge, the strength of the shell and the size of the stars is the foundation for the width of the display.
The elements like calcium emit less energy and correspond to the brilliant orange with a longer wavelength. The mixture of Strontium and copper with its oxides and carbonates has violet hues, which is the most difficult one to create. Barium compounds have green shades while crimsons and corals from Lithium compounds. Technological advancements made it possible to create multiple hues canvas capturing millions to the show.
The mineral collection seems to baffle at first, however the passionate mineral lovers graduate quickly in the search for the treasures lying under the earthen layers. Every mineral collection is unique and it’s the personal interest lies with the collector. Before collecting, tap those abundant literary resources, read mineral publications, create a network with masters of rocks. The next step would be the choice of land to start collecting. Safety first followed by permission to access the place. Plan a short visit to some museums or international shows on Mineral exhibitions to see the natural beauty in front of you. Identify your interest and what you look into the field really matters.
Some of the tools that help the collection is as follows. The Estwing prybar and crack hammer are the pre-requisites on every field trip. The more heavy the hammer, the larger the size of the specimen you have in your cart. Then safety within the woods is important as there is the probability of losing your path when it is dark. Mobile maps and GPS can sort you only to a limited extent due to the selective signal availability of the service providers. They cannot capture signals in the mountains or lower horizons. Procuring an altimeter reduces the scene, the pressure sensor and LCD display indicates the altitude and weather conditions.
An internal frame backpack is the most suited carriage for all your specimens. It not only holds in large rocks but also balance the weight through the hips, that enable us for an easy walk. Perspiration and dehydration due to heat often turn down the pleasure of your journey through woods. It often wet the clothes and socks. With Coolmax T-shirt and sunglasses gives a more comfortable hike with good vision. Apart from that, the pocket tools and sledgehammer too can assist the trip making it a memorable one.
The close analysis of rocks, sediments minerals and other substances which are invisible to the naked eye are challenging tasks to the field mineralogists. If they are equipped with a portable hand lens, things will go easy and quick. Identification of the rocks and sands, the shape and size and sometimes their design are the common difficulties faced by them. Field trips and observations largely aid to identify the specimen, however, some minute features are often misinterpreted due to lack of a lens or magnifier.
The size and shape of fossils, crystals or even sand can be a hurdle when a large number of specimens is dealt at once. Many field workers use a hand lens and are seen tied around their neck or shirt pocket. There are also other tools that accompany them during their excavations into the dense world of mineral sands. Rock hammer, hand lens, camera, topographic map, field notebook, and Brunton compass are some of the tools that favour a geologist most commonly.
The hand lens is a small portable magnifying glass with a magnification of 10x. It easily slides into the pocket, opens the protected mode when not in operation, preventing scratches and ruins. It is handy, and weightless so as to tie the cord around the neck with a knot beneath the pivot hinge. The Kruss Pocket Loup is the most convenient tool among all glasses. It fits into the pockets, wallets or even in vehicles. It comes with the leather casket and also protected to reserve lens inside a desk drawer or bookshelf. It’s also 10x power glasses which finds application over extensive areas like gemology, jewelry check, printing, coin/stamp collection etc.
The soft leather lanyard from Gfeller is another tool where the lens is attached and can be easily worn around the neck. These help to prevent the risk of loss of keys, knife or lens.