But, They don't make jewelry out of lithium metal, only lithium niobate, which is a rare crystal. 'Lithium is an alkali metal, which under standard conditions it is the lightest metal and the least dense solid element. Lithium is highly reactive and flammable. Lithium exhibits a metallic luster, but contact with moist air corrodes the surface quickly to a dull silvery gray, then black tarnish.' I would check again with whomever you got it from...