Gold is the oldest precious metal known to man. The story of gold is as rich as the metal itself. Of all precious metals known to man; only gold combines lustrous beauty and easy workability. Gold was discovered about 8,000 years ago and was used by pharaohs in ancient Egypt as far back as 3000 BC. It was used for the first time as money in about 560 BC in the Kingdom of Lydia, the modern day Turkey. Greece and Rome both left rich legacies of golden treasures, but after the fall of the Roman Empire, little gold was produced in Europe or Asia for almost a thousand years.
A Metal like no other!
From ancient times, no other metal has fascinated mankind as gold has; nor has any other metal inspired the creative human minds like an intricate craftsmanship in gold. Gold is so soft and malleable that one gram can be stretched into a wire 3 ½ kilometers long. One ounce or 31.1035 grams can be hammered into a sheet so thin that it can cover a 16 sq meters area. Gold is virtually indestructible as it does not rust, tarnish or corrode. Coins found in sunken galleons are as bright and shiny as the day they were cast.
The Different Karatages of Gold
Karat is the term used to measure the gold content or purity. 24 karat gold contains 24 parts pure gold, while 22 karat gold contains 22 parts gold and 2 parts of other metals added as alloy. 21 karat gold contains 21 parts gold with three parts of other metals added. 18 karat gold contains 18 parts pure gold with 6 parts of other metals added. In the West the karat is expressed in fineness. For example, 24 k gold is expressed as 1000 parts out of 1000 pure or fineness 1.000. 22 k is expressed as 22 divided by 24, multiplied by 1000, which will give you a fineness of .9166, 21 karat is 21 divided by 24 multiplied by 1000 which is .875 fineness and similarly 18 karat is .750 fineness.
The Different Colors of Gold
24 karat gold has the natural warm color of pure gold and its color cannot be changed without changing the purity to less than 24 k. Other colors of gold can be made by changing the composition of the alloy in the making of the jewellery. Pink gold for example is made by adding more copper in the alloy composition of the gold. Likewise green gold is more of zinc and silver and white gold is more of nickel. A surface color can also be given to gold articles by electro-plating. However this can only be a surface finish and will wear off over a period of time.