A metal that was frequently used in fashion jewellery and occasionally as an alloy in gold jewellery. However, some people have an allergy or skin reaction to nickel which results in a rash, particularly if worn as pierced jewellery such as earrings. Recent European legislation (the Nickel Directive) strictly defines the amount of nickel that jewellery can contain, to ensure that it remains far below the level at which such skin reactions could become likely.