Cobalt canyon in the side of a mountain. The firm Calera Mining Company started production at the site. The stable form of cobalt is produced in supernovas through the r-process. It comprises 0.0029% of the Earth's crust. Free cobalt (the native metal) is not found on Earth because of the oxygen in the atmosphere and the chlorine in the ocean. Both are abundant enough in the upper layers of the Earth's crust to prevent native metal cobalt from forming. Except as recently delivered in meteoric iron, pure cobalt in native metal form is unknown on Earth. The element has a medium
Cobalt boride Cobalt boride nanoparticless in the size range of 18 to 22 nm have also been produced. When used as a catalyst, cobalt boride is prepared by reducing a cobalt salt, such as Cobalt(II) nitrate, with sodium borohydride. Prior to reduction, the surface area of the catalyst is maximized by supporting the salt on another material; often this material is activated carbon. Cobalt boride Cobalt borides are inorganic compounds with the general formula CoB. The two main cobalt borides CoB and CoB. These are refractory materials. Cobalt boride is known to be exceptionally resistant to oxidation, a chemical property which makes