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Friday, March 2, 2012

GOLD




The shiny and yellow metal known as gold has always kept humans fascinated. We have used it for jewellery, amulets and decorations since prehistoric times. There is evidence of gold being used in Central and Eastern Europe as early as 4000 B.C. The Bible mention gold in the second chapter of Genesis, and archaeologists have found 4000 year old documents describing the search for gold in Egypt . The oldest pans – big discs used for finding gold in rivers – date back to the Mayan civilization. 

Because of its physical characteristics gold has always been linked to the sun and often even believed to have been formed by sun beams. The Romans called gold” aurum” which is also the Latin word for morning glow, the Greek Goddess of Dawn was named Aurora , and the ancient Hebrew word for light is aor .
Pure gold is soft and malleable in is therefore often mixed with other metals to form stronger alloys. The gold content is measured in carat , where pure gold is 24 carats. If you have a piece of 18 carat golden jewellery it means that 18/24 of the alloy is pure gold, 75 percent. At 8 carat, only one third the alloy will be pure gold. 

In jewellery gold is often alloyed with copper and/or silver. Since copper is red, it will give the gold warmer and more ruby glow. Silver, and all other metals, will add white or grey shades to the gold. So called “White Gold” was developed during the 1920's as an alternative to the costly platinum. There are two types of white gold: Palladium whites and Nickel whites. The strongest “bleachers” used to form white gold are nickel, palladium and the expensive platinum. Nickel is popular since it is low-priced, but has several disadvantages including being highly allergenic.
There are two different kinds of deposits where you can find gold; placer and lode . Placer deposits are areas where you can find free gold that has been separated from its original place by natural forces such as erosion. Lode deposits are found underground, where the gold is usually mixed with quartz. The most romantic method of gathering gold from placer deposits is the well known panning method. Panning is one of the most rapidly growing hobbies in the U.S. today. Panning works, since gold has a comparatively high density and will stay on the bottom of the pan after most other debris has surfaced and been washed out. There are several resorts in the U.S. where you can spend your holiday searching for gold and learning more about its fascinating history.
Gold is not only loved for its beauty; scientists, doctors and engineers love it for its extraordinary chemical and physical properties as well. A lot of equipment necessary in our modern society requires gold to function. Gold is the most malleable and ductile of all the metals, and can therefore be used to create strong but super-thin metallic threads to use in conductors, which is especially imperative in computers and equipment used for telecommunication. 

The fact that gold is one of the best conductors of electricity is an additional plus. Gold is also a first-class conductor of thermal energy and is used in the engine nozzle of the Space Shuttle to remove heat, preventing it from melting where temperatures can reach as high as 3300° C (5970° F) . Furthermore, gold is used in the astronaut's shields since it is the best material for reflecting infrared energy. A golden surface will reflect up to 99 percent of the infrared rays. Gold is also very popular in the health care industry, since it is non-toxic as well as non-corrosive.

"If money is your hope for independence you will never have it. The only real security that a man will have in this world is a reserve of knowledge, experience, and ability."

- Henry Ford

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