What is gold?
The ancient Egyptians believed that gold was the flesh of the gods, and were wonderful goldsmiths producing some of the most beautiful gold-work the world has ever seen. In Greece it has left us with the tale of “Jason and the Golden Fleece” one of the greatest adventure stories ever told. The Romans believed that it was the “shining dawn” the Latin word for gold is “aurum” that has given us our atomic symbol for gold Au. It is been treasured by men since ancient times where it has been used in coinage, jewelry and other places since the beginning of recorded time. There have been wars fought over gold, worlds conquered, great migrations, gold rushes, some of the greatest literature ever written and it is al in the name of Gold.
The metal occurs in nature sometimes as nuggets and particles as fine as flour, at other times as grains or crystals in certain rocks. Gold quartz is one of its most common ores, but not the only one, gold is where you find it. Most of the ancient gold that was discovered is what is called alluvial gold found in the sands and gravels of the beds of streams and rivers. It wasn't until men learn how to mine in hardrock that gold was won from gold bearing veins.
The metal gold itself is a dense, soft, shiny metal that is the most malleable and ductile metal known to men. A troy ounce of gold can be beaten into a sheet covering one-hundred square feet, or drawn into a wire fifty miles long. Gold has an atomic number of 79 on the periodic table of elements and has a density of more then 19 times greater than water. Its color is a very great, shiny yellow that many have likened to the color of the rising Sun.
Since ancient times gold has been valued as a monetary metal. The oldest coins that were ever found were made from gold. These were gold coins that were invented by Midas the King of Lydia a kingdom that was on the Anatolian peninsula (Modern Turkey). From ancient times until the present gold is one of the metals from which coins are struck. Throughout history gold has been a symbol of wealth and also a store of value. Standards are based on gold have always provided a basis for the establishment of monetary policies throughout the world.
As of 2009 the total amount of gold that has ever been mined only amounts to 161,000 tonnes. Translated into Troy ounces this is roughly 5.17 5,000,000,000 ounces. If you wanted to measure its volume it would be about 8,333 cubic meters or a block that measures 20 meters on a side.
Gold has the distinction of being the most recycled metal in the world; some of the gold in the ring you may be wearing was probably worn by one of the pharaohs of ancient Egypt.
Gold is mostly used as a store of value but it has developed many industrial uses it not only jewelry, but in dentistry and various electronic devices. The visor on the helmet of Neil Armstrong, the first man to step foot on the moon was coated with a layer of gold that was only about one atom thick. This coating was to keep out the intense rays of sun.
Gold is also used in electronics because it has a very good resistance to oxygen and other chemicals as well as having a height value as a conductor of electricity.
Gold has traditionally been considered a noble metal because it doesn't corrode. It is not affected by oxygen or acids except for aqua regia that is a mixture of concentrated hydrochloric and nitric acids. Another chemical that will react with gold as an alkaline solution of cyanide; this reaction is often used to recover gold from its ores in the heap leaching process.
To the chemist, gold is a transition metal that can form both trivalent and univalent cations when found in a solution. When compared to other metals gold is the least chemically reactive. However, gold will dissolve in mercury where it forms an amalgam alloy that is the basis of its use in dentistry.
Because gold is not attacked by nitric acid alone but other metals like silver and other base metals are, this is one of the properties used in refining gold that is known as the “inquartation and parting” process where the other metals are dissolved and the gold is left behind. The same principle as found in this process has also given rise to the saying to give something the “acid test.” When used this way it is referring to a gold standard test for determining something’s real value.
References:
Gold, Wikipedia, http://en.wikipedia.org/wiki/Gold
The Mineral: Native Gold