Barium

In nature, barium is found in the Earth's crust, 0.05 % (w/w), in minerals such as barite and witherite [8]. The isotopes found in nature are ¹³⁰Ba (0.101 %, stable), ¹³²Ba (0.097 %, stable), ¹³⁴Ba (2.42 %, stable), ¹³⁵Ba (6.59 %, stable),¹³⁶Ba (7.81 %, stable), ¹³⁷Ba (11.32 %, stable) and ¹³⁸Ba (71.66 %, stable) [8].

In pure solid form, barium exist in a body-centered cubic crystal form [8]