Lithium is an element with atomic number 3, symbol Li. The most abundant isotope, atomic weight 7, is stable, and one more isotope, atomic weight 6 is also stable.
Lithium is thought to have been formed in the Big Bang and in Cosmic Ray Spallation in stars, i.e., Fusion produced by Cosmic Rays (beta particles). Main Sequence Stars lack lithium because it burns at a Temperature less than Hydrogen burning.
Brown Dwarf (BD)