* Nickel sulfide: This is the most common nickel compound found in nature. It is a black mineral that is often found in association with copper and iron sulfides.
* Nickel oxide: This is another common nickel compound that is found in nature. It is a green mineral that is often found in association with nickel sulfide.
* Nickel carbonate: This is a white mineral that is found in nature. It is often used as a source of nickel in industrial applications.
* Nickel sulfate: This is a blue-green compound that is used in a variety of industrial applications, such as electroplating and metal finishing.
* Nickel chloride: This is a yellow-green compound that is used in a variety of industrial applications, such as metal finishing and photography.
Nickel is also found in a variety of other compounds, such as nickel alloys, which are mixtures of nickel and other metals. Nickel alloys are often used in industrial applications where strength and corrosion resistance are required.
