Wikijunior:The Elements/Gold
Gold is a yellow precious metal that is valued for its beauty and shine. Gold is softer than many other metals and can be formed into different shapes using simple tools and without fire or other heat. Because it can be found in clumps and is easy to work, it is believed to be the first metal that was used by humans. It has been used for making coins and jewelry for thousands of years. Today it is still used to make jewelry. Because it is a rare metal, it is a symbol of wealth. It is also used in electronic devices such as computers.
Gold may be worked into all sorts of shapes. It can be rolled into tiny shapes. It can be pulled into thin wire, which can be twisted and plaited. It can be hammered or rolled into sheets. It can be made very thin, and stuck onto other metal. It can be made so thin that it was sometimes used to decorate the hand-painted pictures in books called "illuminated manuscripts".
Gold does not "react" with many other chemicals. This means that it does not lose its shine, or rust, or burn, or explode. When ancient gold coins or jewellery are found, they look as shiny and beautiful as the day they were made.
Where did its name come from?
editGold gets its English name from the Germanic word gulþa (meaning gold). The Old English word geolu means yellow. In Latin, gold was called aurum. This is why the chemical symbol for gold is Au.
Where is it found?
editGold is rare, which means it is difficult to find. Gold is usually found underground, where it is dug out of mines that are tunnelled deep into the earth. Gold is usually found as thin layers in rocks, but is also sometimes found in lumps. A lump of gold is called a nugget.
Gold can sometimes be found above the ground in the sand and gravel bars of streams. Flakes and grains of gold that are trapped in rock come loose as the rock is broken up by the force of the water. The water then carries the gold downstream. When the stream slows down, the gold settles along with sand and gravel. People sometimes look for loose gold in streams, or in places where streams have once flowed. This is called "prospecting". A prospector often carries a wide pan, to scoop up the sand and gravel from the bottom of a stream and swish it around, looking for tiny flakes and nuggets of gold. This is called "gold panning".
Is it dangerous?
editGold is not dangerous. Very pure gold leaf (sometimes called "edible gold") is safe to eat and is sometimes used to decorate food. Gold is so safe to put in your mouth that many people have false teeth and fillings made of gold. Sometimes gold has "impurities". This means that small amounts of different elements are in the gold. The impurities in the gold may be poisonous.
Did You Know?
- Gold was probably the first metal used by humans.
- Gold is so soft that people used to bite gold coins to make sure they were real.
- A single gram of gold can be pounded into a sheet of gold leaf covering a square meter.