Lithium has atomic number 3 and, along with Hydrogen and Helium, was present (at a much lower level) in the early universe. The Earth's crust contains about 20-

Lithium has atomic number 3 and, along with Hydrogen and Helium, was present (at a much lower level) in the early universe. The Earth's crust contains about 20-70 parts per million (ppm) of lithium. It may be tedious to extract, but it is not like we will ever run out.