Throughout history gold has often been seen as a symbol of wealth.
Gold is the most popular precious metal for investments.
As of 2009, it has been estimated that humans have mined around 160000 tonnes of gold.
The amount of gold in various alloys (a combination of gold and another metal such as silver) is measured in carats (k). Pure gold is 24k.
24 karat gold is pure elemental gold. 18 karat gold is 75% pure gold. 14 karat gold is 58.5% pure gold, and 10 karat gold is 41.7% pure gold. The remaining portion of the metal usually is silver, but may consist of other metals or a combination of metals, such as platinum, copper, palladium, zinc, nickel, iron, and cadmium.
Over the last 100 years South Africa has been the biggest producer of gold. In recent times however it has been surpassed by China.
As of 2009, the USA has 8133 tonnes of gold reserves while Canada only has 3.
Gold is the only metal that is yellow or "golden". Other metals may develop a yellowish color, but only after they have oxidized or reacted with other chemicals.
Nearly all of the gold on Earth came from meteorites that bombarded the planet over 200 million years after it formed.
The element symbol for gold is Au. The symbol comes from the old Latin name for gold, aurum, which means "shining dawn" or "glow of sunrise".
An african gold mining worker
The word "gold" comes from the Germanic languages, originating from the Proto-Germanic gulþ and Proto-Indo-European ghel, meaning "yellow/green". The pure element has been known since ancient times.
Gold is extremely ductile. A single ounce of gold (about 28 grams) can be stretched into a gold thread 5 miles (8 kilometers) long. Gold threads can even be used as embroidery thread.
Although gold is a heavy, dense metal, it is generally considered non-toxic. Gold metal flakes may be eaten in foods or drinks.
Gold is a noble metal. It is relatively unreactive and resists degradation by air, moisture, or acidic conditions. While acids dissolve most metals, a special mixture of acids called aqua regia is used to dissolve gold.
Gold has many uses, aside from its monetary and symbolic value. Among other applications, it is used in electronics, electrical wiring, dentistry, electronics, medicine, radiation shielding, and to color glass.
High purity metallic gold is odorless and tasteless. This makes sense, since the metal is unreactive. Metal ions are what confers flavor and odor to metallic elements and compounds.
Gold is a good conductor of electricity and heat.
Gold is shiny, soft and dense. It is also malleable, which means it can easily be beaten into thin sheets or other shapes.
Gold is malleable enough for just 1 gram to be hammered into a sheet 1 square meter in size. It can also be made so thin that it appears transparent.
The price of gold continually fluctuates and is often linked to major economic events.
There is a monetary system called the ‘gold standard’ which fixes a unit of money to a certain weight of gold.
Over the years gold has been used to create expensive jewelry, coins and various forms of art such as the Egyptian pharaoh Tutankhamun’s famous burial mask. In modern times it has also been used for things such as electronics and dentistry.
Injectable gold has been proven to help reduce pain and swelling in patients suffering from tuberculosis and rheumatoid arthritis.
Gold is a popular choice when it comes to rewarding achievement with medals, statues and trophies. Academy Award, Olympic and Nobel Prize winners all receive golden items in recognition of their achievement.