A Silver Coloured metal
Nickel is a silver coloured element usually found in its metallic form. It is very resistant to corrosion and does not rust in the way that steel does hence it is often mixed with other metals to create a corrosive free alloy. Its is often used for the manufacture of coins, batteries and all manner of metal objects ranging from musical instruments to cutlery. It was also used widely in jewellery. The rings on the left are pure nickel and as you can see look like silver except their colour will change to a dull brown over time.
Some people can develop a hypersensitivity to Nickel particularly when the particles of nickel are dissolved by sweat and excess amounts of nickel enter the blood systems. This can lead to nasty skin reactions caused by nickel molecules binding to to the skin cells. Medical advice and assistance may be required in extreme cases. Nevertheless most people rarely realise how much nickel they encounter in their every day lives, such as using cutlery for eating. It is therefore crucial for a reaction to develop, that there is a prolonged exposure to nickel. A common example will be a rash developing around the belly from wearing a nickel plated belt buckle.