Copper is a soft metal that is an essential element for enzymes and life, gives octopuses their blue blood and was often used to make coins. Allan Blackman from AUT has the lowdown on copper in ep 23 of Elemental.

The metal copper is an important constituent of the human body - in the right amount. It's involved in enzymes, cellular respiration, and the synthesis of hormones and melanin, but too much or too little is bad for us.

Copper is also why octopuses have blue blood.

It can be found in nature as the pure metal (no refining needed) and the name copper originally meant 'metal from Cyprus.' Its chemical symbol is Cu and its atomic number is 29.

On its own it is too soft to be very useful, but combined with either tin or zinc it creates the useful alloys bronze and brass, respectively.

It has traditionally been used as a coinage metal. It is an excellent conductor, which is why it was used in copper phone lines and power lines.

Go to this episode on rnz.co.nz for more details