Lithium

What is Lithium?

The lightest known metal, lithium is the leading element of the alkali metals group. It is the least dense metal and the least dense solid element at room temperature. Lithium is a good conductor of heat and electricity, as well as a highly reactive element. It is soft enough to be cut with a kitchen knife and so low in density—roughly the same as pine wood—that it is one of only two metals that float on water. 

Lithium is found in igneous rock, with the largest concentrations in granites. Granitic pegmatites provide the greatest abundance of lithium-containing minerals, with spodumene, petalite, and lepidolite being the most commercially viable sources. Due to its solubility as an ion, lithium is also present in ocean water, salt lakes, and geothermal brines. In a process cheaper than mining and processing of lithium-bearing hard rock, brines are pumped to the surface where the lithium concentration is raised through solar evaporation in a system of ponds, a process that can take up to 18 months.

Brazilian naturalist and statesman Jozé Bonifácio de Andralda e Silva discovered the mineral petalite on the Swedish isle Utö in the 1790s. In 1817, Swedish chemist Johan August Arfwedson first succeeded in isolating one of lithium’s salts from petalite. Not until 1855 did British chemist Augustus Matthiessen and German chemist Robert Bunsen separate the lithium element by running a current through lithium chloride.

Fun Facts

• Because virtually all rocks contain trace amounts of the element, lithium got its name from lithos, the Greek word for “stone.”
• Natural lithium is white to gray in color, but when thrown into fire it flares bright crimson. And like sodium, if you drop lithium into water it bursts into a red flame.
• Lithium is one of only three elements (hydrogen and helium being the others) created when the universe formed but, according to the Big Bang Theory, the universe should hold three times as much lithium as can be accounted for in the oldest stars, a conundrum known as the Missing Lithium Problem.
• The first major application of lithium was in high-temperature lithium greases for aircraft engines during World War II.