Discovered : known in India and China before 1500 and to the Greeks and Romans before 20 BC as the copper alloy brass Origin : The name is derived from the German ‘Zink’. Description : A grey metal with a blue tinge. World production exceeds 7 million tonnes a year and it is used to galvanise iron to prevent it rusting. It is also employed in alloys and batteries, and as a zinc oxide to stabilise rubber and plastics. Zinc is essential for all living things, and is important for growth and development. The average human body contains about 2.5 grammes and takes in about 15 milligrammes per day. Some foods have above average levels of zinc, including herring, beef, lamb, sunflower seeds and cheese. Image : Alchemical symbol.