Cobalt

In nature, cobalt is found in the Earth's crust, 10-20 ppm, in minerals such as cobaltite, linneaite, smaltite and erytrite [6]. The isotope found in nature is ⁵⁹Co (100 %, stable) [6].

In pure solid form, cobalt exist in two forms: hexagonal and cubic form. Of these, the hexagonal form is the most stable form at room temperature [6]