Precious metals

Sofia loves listening to Maria’s stories about pirates. She thinks of the treasure chests buried on desolate islands, filled with silver and gold. But why is it always silver and gold? Surely metal that can be made into swords and armour should be more useful or valuable! What is so special about gold and silver?

Why are they so precious? Gold and silver are not as common as other metals, such as aluminium, iron, zinc, or nickel. Gold and silver are rare. The rarer and harder to obtain something is, the more value it usually has. It is partly because of their rarity that silver, gold, platinum and a few other metals are considered precious metals.

But there are other reasons too. Let’s look at a non-precious metal: iron. What happens to iron if it’s left outside? A chemical reaction occurs that causes iron to corrode. The iron rusts.

Many other metals, when exposed to certain conditions or substances, undergo such reactions too. And when metals corrode, they often lose their strength, colour, shininess or other properties. But gold, silver and platinum do not react easily with other substances. We say they are noble metals. Their low reactivity makes them corrosion-resistant.

This allows them to retain their shine and quality for a long time, even in harsh conditions. Another property of precious metals is their softness. This was useful in the past, when gold and silver were used to make coins. Their softness made them easy to stamp and make into a coin — to mint. Silver and gold are also easy to shape and stretch, even into very thin sheets.

These sheets can be used to cover decorative ornaments, such as picture frames, or in art. Because of their softness, attractive look, and value, precious metals have also been a popular choice for jewellery for thousands of years. If needed, the strength and hardness of precious metals can be increased by mixing them with other substances to make alloys. Precious metals and their alloys have many other uses in the areas of economy, technology and industry. For example, gold and silver have been used throughout history as a financial “backup” or reserve for other forms of money, such as banknotes.

Gold, silver, and platinum are used to make parts for engines, laboratory equipment, and solar panels. Most electronic devices, such as smartphones, computers, and tablets also include some precious metals. Precious metals also have a number of applications in medicine and dentistry. They are used in medical equipment and treatments, and fillings and dental crowns are often made of gold and silver alloys. Gold is even used to make space suits and spacecraft, as it protects against radiation and heat.

So sure – silver and gold don’t make great armour or swords, but their rarity and physical properties make them both valuable and useful for so much more!