Gold and Silver
We rely on gold and silver every day – you are using them right now as you read this on your computer screen.
Gold bars and coins are the popular image of this precious metal, but it has many practical uses.
We rely on gold and silver
Each year the Martha and Favona mines produce, on average 100,000 ounces of gold and 750,000 ounces of silver.
The prices of gold and silver on the world market change every day. Between January and August 2011 the price of gold ranged from $US1,320 to $US1,800 per ounce and silver ranged from $US30 to around $US50 an ounce.
Why are these precious metals so special and so costly?
We know there’s lots of gold and silver in banks, and we’ve seen pictures of expensive gold and silver jewellery. But there are many ways we use and rely on gold and silver every day.
- gold and silver are very good conductors of electricity and heat
- both can be alloyed (mixed) with other metals to produce new materials
- gold and silver are malleable—they are easily shaped, and very ductile—they can be stretched out into very thin wires
- gold and silver do not chip, flake or corrode
- gold and silver can be recycled.
In your home gold and silver are used in electronic circuits. It is likely that your television and your computer have gold circuits in them, probably your PlayStation too. Don’t bother pulling them apart though. The amount will be small, probably in wires thinner than your hair or in very small printed circuits.
Stereo systems sometimes use gold plated interconnect cables. The gold provides a better contact, and so a better sound.
There could be some silver on your wrist right now, or it could be disguised and hanging around your neck. No, not jewellery. The button batteries used in digital watches contain silver. Similar batteries power a large range of devices.
Silver is also used in some water filters, and although it may seem strange, it is also used in the production of some man-made fabrics. You could be wearing small amounts of silver right now within your clothing.
Gold is used by dentists to make crowns for teeth. Gold and silver is used in hospital too. Burn creams contain silver, gold leaf is used to treat some ulcers, and those special surgical lasers will use gold and silver.
Need glasses? Photochromatic lenses – those are the ones which go darker when the sun gets brighter – contain gold.
Gold and silver are in many places in your everyday life – often where you least expect them.
Who would have thought that at the very top of the Auckland Sky Tower there is a gold plated ball. It’s there so that if the tower gets struck by lightning the electricity will strike the ball and be conducted safely to the ground.