Nickel is a silvery-white lustrous metal with a slight golden tinge that takes a high polish. It is one of the four magnetic elements that are magnetic at room temperature. It belongs to the transition metals and is hard and ductile. Its use has been traced as far back as 3500 BC, but it was first isolated and classified as a chemical element in 1751 byAxel Fredrik Cronstedt, who initially mistook its ore for a copper mineral. It’s most important ore minerals are laterites, including limonite, garnierite and pentlandite. Major production sites include Sudbury in Canada and in Russia. The metal is corrosion-resistant, finding many uses in alloys, as a plating, in the manufacture of coins, magnets and common household utensils, as a catalyst for hydrogenation, and in a variety of other applications. Enzymes of certain life-forms contain nickel as an active center making the metal essential for them.