Copper Properties, Facts and Photos
What is Copper?
Copper is a reddish-brown coloured chemical element. It was the first metal to be used by humans and the first metal to be smelted. This is the process of extracting a metal from an ore by heating and melting.
The history of copper can be traced back at least 10,000 years.
Imported by the Roman Empire from Cyprus it was originally called "aes cyprium" meaning "metal of Cyprus". The name was later shortened to "cuprum."
Copper is widely used in industry because it resists corrosion from air, moisture and sea water. It conducts electricity and heat hence is used in pipes, wiring, heating, cooling applications and cooking pans.
It's often alloyed with other metals including brass which is copper and zinc. Bronze is copper, zinc and tin although other elements are often added.
Sterling silver is 7.5% copper 92.5% pure silver.
Even though copper is used as an alloy to strengthen silver it's actually quite soft. With it being ductile and malleable it hardens after being shaped and hammered. When heated in can be softened again.
Although many people believe silver tarnishes, in its purest form it does not tarnish. The tarnish on sterling silver comes from the copper.
Copper is an important trace element vital for the health of all living organisms. It can be found in a wide range of foods.
As well as being a chemical compound copper also occurs as a native element. Known as native copper, this means it occurs naturally in its pure metallic state without the need for refining or processing.
Native elements are minerals formed from a single chemical element. Gold, sulfur and carbon are all native elements.
Native copper is typically found as irregularly shaped masses or dendritic crystals in copper-rich ore deposits.
The copper most of us are used to seeing is typically extracted from copper sulphide or oxide ores. This is done through a refining process that involves smelting and electrolysis to remove impurities and refine the copper to a high purity.
The main difference between native copper and the more familiar copper is purity and composition. Native copper is essentially pure copper. The variety used commercially is more likely to contain impurities. These are usually other metals, sulphur and oxygen.
Native copper can be used directly without any refining whereas the other must be processed to remove impurities before it can be used.
In terms of appearance, native copper typically has a distinctive reddish-brown colour and a metallic lustre. Manufactured copper tends to be a darker shade of brown due to impurities.
By 8000 BC native copper was being used in place of stone. In ancient Egypt around 3500 BC it was being alloyed with tin to produce bronze.
Most copper is extracted from ores. An ore is a rock or mineral that contains important elements and metals in sufficient quantities to make extraction worthwhile. The quantity is usually very small.
Malachite is the oldest ore of copper. Today chalcopyrite is the most abundant ore of copper.
The Keweenaw Peninsula of Michigan has one of the world's largest concentrations of native copper.
Prior to 1992 coins in the United Kingdom contained 97% copper. This meant the 2p coin contained 6.9 grams and the penny 3.45 grams.
As market price increased the amount of copper being used was reduced. From 1992 1p and 2p coins have been manufactured from steel with only a thin plate of copper. From 2006 the coins were worth more as scrap than their face value.
The copper in our first photo is courtesy of Stan Celestian. The second photo was taken by Stone Mania in the Harvard Museum of Natural History, Massachusetts.
The last photo is chalcopyrite. Photo courtesy of Ron Wolf.
All photos are clickable redirect to the original non-compressed images.