THE CHEMICAL SYMBOL of gold is AU from Aurum, the Latin word for gold. Chemically gold is an element, which means it cannot be broken down further. Interestingly, in the Periodic Table of Elements (below) gold occupies the same group, i.e. Group 11, as copper (Cu) and silver (Ag) that also played the role of money in the history of mankind.
Karat grade is used to express the purity of gold. It basically refers to the proportion of gold in an alloy. Pure gold (100 per cent) is 24 karat. The proportions in other karat are as in the table below.
- As an element, gold cannot be further broken down by chemical means. Hence it is indestructible and permanent.
- Gold is also such an inactive metal that it is not affected by air and water, i.e. does not oxidize (tarnish, rust or corrode). Gold artefacts unearthed in the Egyptian pyramids still look new and bright.
- Gold is highly malleable (i.e. the ability to be pound into thin sheets) such that a single ounce of gold can be hammered into a 100 squarefoot sheet.
- Gold can be hammered so thin that sunlight can shine through it. A pile an inch high can contain more than 200,000 sheets!
- Gold reflects infrared rays while allowing sunlight to pass through, hence its use in astronaut helmets and window glass.
- Gold is most ductile (ability to draw out into wire) that a single ounce of it can be drawn out into a 50-mile long wire!
- Gold is so rare that only about 90,000 tons of it have been taken from the earth in recorded history
- South Africa is the largest gold producing country in the world. Other leading producers include Russia, Canada, and the United States.
- Gold is so heavy that one cubic foot of it weighs half a ton.
- All the gold in the world could be compressed into an 18-yard cube.
- Gold has been used by man for more than 6000 years.
- In 1933, President Franklin D. Roosevelt banned the private ownership of gold, which was then lifted on December 31, 1974.
- Gold is said to be a cure for rheumatoid arthritis. It is chemically liquefied and injected into the muscles of arthritic patients. It is said that the treatment is successful in seven out of ten cases.