Nickel

Magmatic sulfide
Magmatic sulfide describes valuable mineral deposits formed within mafic and ultramafic igneous rocks through magmatic processes. These deposits contain minerals particularly rich in the metals nickel, copper, and platinum.
Whenever magma cools and crystallizes, sulfide minerals of higher density tend to sink and segregate. This produces elevated concentrations of higher-density metal salts. These deposits are often found in igneous geological complexes, particularly in layered intrusions or volcanic conduits. Magmatic sulfides are vital in global metal supply, as pre-concentrated deposits that render high value in mining and refining.

Laterites
Laterites are weathered soils and rock formations. They are generally characterized by a distinctive red or brown color and high levels of iron and aluminum oxides. Laterites are formed in tropical and subtropical regions with heavy rainfall and higher environmental temperatures. They develop as a result of intense chemical weathering over extended periods. This process leaches minerals from the upper layers and concentrates metallic salts in the lower layers because of their generally higher densities. Laterites are commercially valued for extraction as they can also contain concentrations of high-value minerals like nickel and cobalt.

Nickel is found in metallic meteorites, so it was used by ancient man. Artifacts dating as early as 5000 BC made from nickel-containing meteoritic metal have been found in Egyptian graves. However, nickel wasn't recognized as a new element until Swedish mineralogist Axel Fredrik Cronstedt identified it in 1751 from a new mineral he received from a cobalt mine. He named it an abbreviated version of the word Kupfernickel. Kupfernickel was the name of the mineral, which roughly translates as meaning "goblin's copper" because copper miners said the ore acted as though it contained imps that prevented them from extracting copper. As it turned out, the reddish ore was nickel arsenide (NiAs), so it's unsurprising copper was not extracted from it.

Nickel is a hard, malleable, ductile metal. It is a shiny silver metal with a slight gold tinge that takes a high polish and resists corrosion. The element does oxidize, but the oxide layer prevents further activity via passivation It is a fair conductor of electricity and heat. It has a high melting point (1453 ºC), readily forms alloys, may be deposited via electroplating, and is a useful catalyst. Its compounds are mainly green or blue. There are five isotopes in natural nickel, with another 23 isotopes with known half-lives.

Nickel is one of three elements that are ferromagnetic at room temperature. The other two elements, iron and cobalt, are located near nickel on the periodic table. Nickel is less magnetic than iron or cobalt. Before rare earth magnets were known, Alnico magnets made from a nickel alloy were the strongest permanent magnets. Alnico magnets are unusual because they maintain magnetism even when they are heated red-hot.

Nickel is the principal metal in Mu-metal, which has the unusual property of shielding magnetic fields. Mu-metal consists of approximately 80% nickel and 20% iron, with traces of molybdenum.

The nickel alloy Nitinol exhibits shape memory. When this 1:1 nickel-titanium alloy is heated, bent into shape, and cooled it can be manipulated and will return to its shape.

Nickel can be made in a supernova. Nickel observed in supernova 2007bi was the radioisotope nickel-56, which decayed into cobalt-56, which in turn decayed into iron-56.

Nickel is the 5th most abundant element in the Earth, but only the 22nd most abundant element in the crust (84 parts per million by weight). Scientists believe nickel is the second most abundant element in the earth's core, after iron. This would make nickel 100 times more concentrated below the Earth's crust than within it. The world's largest nickel deposit is in Sudbury Basin, Ontario, Canada, which covers an area 37 miles long and 17 miles wide. Some experts believe the deposit was created by a meteorite strike. While nickel does occur free in nature, it is primarily found in the ores pentlandite, pyrrhotite, garnierite, millerite, and niccolite.

While humans don't use nickel for any known biochemical reactions, it's essential for plants and occurs naturally in fruits, vegetables, and nuts.

Most nickel is used to make corrosion-resistant alloys, including stainless steel (65%) and heat-resistant steel and non-ferrous alloys (20%). About 9% of nickel is used for plating. The other 6% is used for batteries, electronics, and coins. The element lends a greenish tint to glass. It is used as a catalyst to hydrogenate vegetable oil.

The US five-cent coin called a nickel is actually more copper than nickel. The modern US nickel is 75% copper and only 25% nickel. The Canadian nickel is made primarily of steel.