Nickel occurs most often in combination with Sulfur & Iron in Pentlandite, with Sulfur in Millerite, with Arsenic in the mineral Nickeline, and with Arsenic & Sulfur in Nickel Galena.
Bulk of Nickel mined comes from two types of ore deposits:
Laterites – the principal ore are nickeliferous Limonite (Fe,Ni)O(OH); Garnierite (a hydrous nickel silicate): (Ni,Mg)3Si2O5(OH)4.
Magnetic Sulfide Deposits, where the principal ore is Pentlandite (Ni,Fe)9S8.
Naturally occurring alloys of Iron & Nickel:
Kamacite – 90:10 to 95:5 ratio, with impurities Cobalt & Carbon.
Taenite – Nickel content between 20% & 65%.
It is silvery-white lustrous metal with a slight golden tinge. It is hard & ductile.
It is one of only four (4) elements that are magnetic at or near room temperature, the others being Iron, Cobalt, & Gadolinium.
Nickel used: 46% for Nickel steels; 34% in nonferrous alloys & superalloys; 14% electroplating; & 6% other uses.