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.