Coming from the Latin word cuprum, meaning ‘island of Cyprus’, Copper is a chemical element with symbol Cu and atomic number 29. With a red-orange colour, it is a highly recognisable metal and is soft, malleable and ductile with extremely high thermal and electrical conductivity. It is often used as a conductor of heat and electricity because of these properties, as well as a building material and a constituent of various metal alloys.
Copper is placed in group 11 of the periodic table, along with silver and gold. All 3 metals share certain attributes, such as being characterised by high ductility and electrical conductivity. Copper is also one of only 4 elemental metals to have a natural colour that is not grey or silver, the others being caesium, gold and osmium.
Copper has a long history – it can be found as a pure metal occurring naturally and it is believed to be the first source of metal used by humans. It was also the first metal to be smelted from its ore, cast into shapes and alloyed with another metal. It was prevalent in the Roman Empire, who obtained most of their copper from Cyprus. Today, we obtain copper mainly from ores such as cuprite, tenorite, malachite, chalcocite, covellite and bornite. Although copper has been used for a long time, more than 95% of all copper ever mined and smelted has been extracted since 1900.
The main use of copper is in the electrical industry with 60% of all copper being used in electrical wires – it is second only to silver in electrical conductance and far more cost effective. It is also widely used to make coins due to the fact it resists corrosion from the air, moisture and seawater. American pennies, for example, are made from zinc coated with copper. The use of copper is also common in building and plumbing. It has been used in rooves, flashings, rain gutters and doors for thousands of years, its distinctive green patina making it highly coveted by architects and designers. In more recent times copper has also been used in interior/exterior wall cladding, building expansion joints and antimicrobial indoor products such as bathroom fixtures.
Pure copper is often too soft for many uses which is why alloying it with other metals is so common. The most common copper alloys are bronze and brass – bronze is a mix of copper containing as much as 25% tin, whilst brass uses between 5-45% zinc.