FILE - Pieces of lithium sparkle in an ore sample in Prague, Czech Republic, on Tuesday, March 28, 2017. Recent explorations confirmed large deposits of lithium near the village of Cinovec northwest Czech Republic. Lithium — the lightest metal on Earth — was discovered by Swedish chemist Johan August Arfwedson more than 200 years ago. Since then, lithium and its compounds have been used in everything from psychiatric medicine to lubricating grease. (AP Photo/Petr David Josek, File)