Copper

Copper Ore Use in the Bronze Age

Ireland had significant copper and gold resources during prehistory, making it arguably, one of the most important metal producing areas in early prehistoric Europe. Copper ore was used to make tools of copper, and later mixed with tin to make bronze tools. Common bronze tools include axeheads, spearheads, knives, daggers, swords and rivets.

• Copper Mining in Ireland

  One of the earliest copper mines in Western Europe is Ross Island, in Lough Leane, Killarney, Co. Kerry. Over thirty copper mines were located at Mount Gabriel in Co. Cork. Copper ores were mined and smelted before being cast into tools, weapons and ornaments.

  The ores were mined using a technique known as fire setting. Fire setting involved setting a fire against the rock face and then throwing water on the heated surface. The copper ores were then prised from the rock face using mauls and hammer stones. The ores were crushed before being smelted. The smelting process involved removing the sulphurs by heating. A waste product was created during this process called slag. As a result of the smelting process the metallic copper could be formed into ingots or ‘copper cakes’ for transport to the metalworkers.

• Using Copper to Produce Bronze

  A new technique of adding tin to copper, in order to produce bronze, was introduced around 2000 BC. This was a major development in metalworking. Adding tin to copper lowered the melting point making bronze easier to work with. The resulting alloy was much harder when it was cast into objects. The Bronze Age metalsmiths gradually worked out that 10 - 12% tin was the optimum amount required to produce quality bronze. Any amount above or below that figure made the metal brittle. The tin used in the bronze tools of the Middle and Late Bronze Age was most likely imported into Ireland from Cornwall. It may have been traded for Irish copper and gold.

• Moulding and Casting

  Bronze Age metal tools were formed using moulds to shape the molten metal into the desired form. The technology for moulding bronze improved through the Bronze Age. Initially, items were cast by pouring the bronze into hollowed out stone moulds. By the Middle Bronze Age, people had invented two part moulds, where two hollowed stones were put together and metal poured into a gap at the top. This allowed for sophisticated objects like axes and spearheads to be produced. By the end of the Bronze Age, metalsmiths were making wax or fat models of what they wanted to cast, putting clay around them and then heating the clay to melt the wax. The melted metal was then poured in and once set, the clay was chipped away. Examples of such moulds are on display in the ‘Prehistoric Ireland’ exhibition at the Museum of Archaeology.

Exhibition links at the Museum of Archaeology

Copper cake and stone mining mauls from Bronze Age Irish copper mines as well as copper axes are on display in the ‘Prehistoric Ireland’ exhibition. This exhibition traces the story of Ireland’s first inhabitants through the Mesolithic, Neolithic and Bronze Age.

Bronze Age Handling Box – Copper

Enquiry Question

How did the use of copper change peoples’ working lives?

Copper Ore in the Handling Box

The Bronze Age Handling Box contains a piece of copper ore.

Teaching About the Bronze Age Using Copper

There are Key Concepts, Key Questions and Learning Outcomes for a range of activities related to Copper. These resources and activities can be downloaded for use in the classroom.