What is GOLD?
Properties and Uses of Gold
BASIC FACTS ABOUT GOLD
CHEMICAL SYMBOL: Au
ATOMIC WEIGHT: 196.967.
SPECIFIC GRAVITY: 19.32 (nearly 20 times as heavy as water)
COLOR: Golden yellow when pure; impurities cause various shades of yellow.
PROPERTIES:
Very soft and easily shaped; extremely resistant to corrosion; nonmagnetic ;excellent conductor of heat and electricity; reacts with very few chemicals.
OCCURRENCE:
Very thinly distributed in earth’s crust and seawater; concentrated in veins in quartz rock and in alluvial deposits.
CHIEF ORES:
Usually found in metallic form; often found as impurity in ores of copper , iron , lead and other metals; also found combined with tellurium as mineral calaverite.
Since ancient times , gold has been one of the most wanted things on earth. People have left their homes and traveled into unknown wildernesses in search of gold. Wars have been fought and kingdoms have risen or fallen because of gold. Columbus was looking for gold when he discovered America.
People have always valued this shiny , yellow metal not only because it is beautiful but because it is scarce. If iron were as scarce as gold, it would be as treasured.
What is gold?
Gold is a soft yellow metal. Its chemical symbol Au, from the Latin word for gold, elements. It is more than 19 times as heavy as water.Gold is one of the most easily worked metals.it is easy to shape and hammer that 1 gram (less than 1/25 ounce) of pure gold be formed into a wire about 1.6 kilometres (1 mile) long. Gold can be hammered into sheets as thin as 0.000076 millimeter (1/1.000.000 inch) .Unlike most metals , gold does not tarnish in the air . it remains bright and shine indefinitely . people probably first valued gold for this special quality.
Gold is one of the least chemically active metals. It reacts with only a few acids. Gold does dissolve in aqua regia, a mixture of hydrochloric and nitric acids, although neither acid alone attacks it. Gold also dissolves in a solution of potassium cyanide or sodium cyanide. The elements chlorine, fluorine, bromine, and iodine combine with gold in the presence of moisture , forming chemical compounds. With mercury , gold forms a liquid alloy that is called an amalgam.
USING GOLD AS MONEY
The most common use of gold has always been as money. Ships loaded with gold from the New World were in constant danger of attacks by pirates who carried their booty to island hideouts. Whenever the pirates managed to return to Europe, their stolen gold made them rich. Although coins also were made of metals other than gold, the value of gold coins was never questioned. But gold did not become a standard for a country’s money until 1821, when Britain adopted gold as its official currency.
By 1914, gold was the measuring stick for almost all the currencies in the world. By having one standard of value , countries were able to trade more easily with one another. Dollars from United States, franc from France, and marks from Germany all had a set value in gold. The currencies could be changed into gold at any time. This system was known as the gold standard. Because of economic difficulties after World War 1, most countries had gone off the gold standard by 1933. Countries such as the United States , Germany , and France store part of their government gold holdings. This gold is called a reserve. It is held in refined bars of uncoined gold known as bullion. Today the gold reserve is not used to back up international trade because of differences of opinion among governments on how this gold should be valued.
OTHER USES OF GOLD
After its use as money , the next most important use of gold is in jewelry and the arts. Gold is made into rings, watchcases, pins and earings. It also is used as a plating , or coating , for costume jewelry. Pure gold is called 24-karat gold. The karat mark on jewelry tells the number of parts out of 24 that are gold. The standard jewelry alloys (combinations of gold with other metals ) in the United States are 10,14, 75% .articles marked "gold-filled" or "rolled gold plate" are made of a base metal (usually brass) covered on one or more surfaces with a old alloy.
Very thin sheets of gold are known as leaf. They are used for decorative purposes – to gild wood, plaster, ceramics, glass, and other substances.
About 15% of the gold not used for money is used in dentistry. This us dates back at least 3,000 years. Gold does not corrode , or rust, in the mouth. It is easily worked into the intricate shapes that are needed to replace or reinforce teeth. Today a variey of gold alloys is used for dental work. Some of these alloys are soft and are used for fillings. Others are hard and strong and are used to replace parts of teeth.
Gold has many industrial uses. Because it is a good conductor of electricity and resists corrosion, it is used for electrical contacts in switches. Electroplated gold has many uses in electric devices, such as on wave guides for radar , on electron-tube grids, and on electrical contacts.
Because gold does not corrode , it is sometomes used in laboratory equipment and in chemical-industry equipment that must resist very corrosive liquids og gases.
Properties and remedies of Dhahab (Arabic) Gold
Gold is evenly balanced. It contains a subtle heat. It is used in carminatives , and fortifies the heart. It is good for the mouth , and sucking it relieves a sre throat.when it is used in cautery, it does not cause blistering and healing is swift. The Prophet Muhammad , may Allah bless and grant him peace, forbade the use of gold and silver containers, but their use as medicines is permitted.
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