How common is lithium in the earths crust?

Lithium, 0.0017%, Technetium, 0%, Bismuth, 2.5×10-6%. Beryllium, 0.00019%, Ruthenium, 1×10-7%, Polonium, N/A. Boron, 0.00086%, Rhodium, 7×10-8%, Astatine, 0%. Carbon, 0.18%, Palladium, 6.3×10-7%, Radon, N/A. Nitrogen, 0.002%, Silver, 7.9×10-6%, Francium, N/A. Oxygen, 46%, Cadmium, 0. read more

Wikipedia's Abundance of elements in Earth's crust article includes estimates from multiple sources. General consensus seems to be that Lithium is the 33rd most abundant element in the Earth's crust (right behind cobalt), at ~20 ppm by weight. read more