The Gold of Western Australia

Gold is a pure chemical element, not combined with any other chemical element, it has one group of atoms and does not form crystals.
It is often found in veins with quartz and sometimes pyrite (fools gold), galena, and sphalerite. These form when hot (between 250-350 degrees Celsius) watery liquid from volcanic rocks deposited the gold and it cooled in a crack in the rock usually about 5-15km below the Earth's surface. Due to weathering and erosion the gold may now be near or on the Earth's surface.

Notice that karat in talking about gold is spelt with a 'k' and when talking about the weight of gems it is spelt with a 'c'. Pure gold is too soft to be used in jewelry.

Karat in gold means 'one twenty-fourth part'. Pure gold is 24 karats, so an 18-karat gold ring contains 75% of pure gold and 25% of other metals like silver, copper or iron. Gold can be 99.8% pure element, but is usually 85-95% pure. Most gold contains some silver. Gold with a higher silver content will make the gold a paler yellow.

Photographed at the Geological Museum

Since 650BC gold was used as the monetary system of the world and even though we have other minerals and paper as money today some banks and governments still keep gold to validate their paper money.

The total amount of gold recovered in the world is around 120,000 tonnes, 75% of which has been mined in the period 1493-1977. All the gold ever mined would make a solid block of metal the size of a small house. This is only a tiny fraction of the planet's total amount of gold.

The chemical symbol used in science for gold is 'Au'. Gold is one of the heaviest metals known except for the platinum group of metals.

Silver. Photographed at the Western Australian Museum

Pure gold has a hardness of 2.5-3 on the Moh's scale.

Gold commonly occurs as irregular plates, flakes, scales, masses or nuggets.

Gold can be easily molded. A single ounce of gold can be beaten into a thin leaf 3 meters square, or drawn out into a wire 80 km long. Gold is virtually indestructible, and does not tarnish but chlorine solutions can dissolve it. Gold is an excellent conductor of heat and electricity and is also highly reflective. Gold is used in industry because of its softness, it blends with other metallic elements, it has electrical and thermal properties, and it is resistance to corrosion.

Gold is turned into a liquid by heat just over 1000 degrees Celsius and no matter how many times you reheat and cool that gold (which only takes seconds for a standard gold bar to cool) it will not loose its properties and will stay nearly 100% pure.

Its used for electrical components in computers along with lots of other things. In 1981 alone, 63 tonnes of gold were used by dentists throughout the world to fill teeth. Did you know gold can even be used in medicines? A small amount of gold is used such as disodium aurothiomalate which is a treatment for rheumatoid arthritis.

About 50% of the world's current production of gold is made into jewelry.