Small amounts of cobalt compounds are found in rocks, plants, and animals, but they are always found in conjunction with other elements and never alone. Cobalt is frequently associated with nickel, and both of these elements can be found in meteoric iron. Metallic cobalt has two crystallographic structures, which are hcp and fcc. Cobalt is protected from oxidation by a passivating oxide film, which makes it a weakly reducing metal. At regular temperatures, cobalt reacts slowly to mineral acids.
Copper is an element commonly used in electrical wiring, roofing, plumbing, and industrial machinery. It is also used in the nutrition industry as a digestible supplement.
Nickel is a chemical element that can be found in stainless steel, alnico magnets, coins, rechargeable batteries, electric guitar strings, microphone capsules, glass tinting solutions, and various alloys. These alloys include nickel brasses and bronzes, and alloys with copper, chromium, aluminum, lead, cobalt, silver, and gold. Nickel is generally considered an alloy metal and therefore is seen in various daily use items.
Zinc (Zn) is chemically similar to magnesium and is the 24th most abundant element in Earth’s crust. The largest zinc supplies are in Australia, Asia, and the US. It is most commonly used to galvanize various metals in order to fight corrosion. Zinc is often combined with copper to create the popular alloy, brass. Not only is brass more ductile and stronger than copper but it also has greater corrosion resistance. Brass is used in communication equipment, hardware, musical instruments, and water valves.