This green variety of the lithium mineral spodumene was discovered by a geologist who commissioned by the inventor Thomas Edison to search for any sources of platinum in North Carolina, USA. Mining began in the 1890s at the discovery site, where Hiddenite occurred alongside emerald and was, for a time, called “lithia emerald” Hiddenite crystals are small, seldom exceeding 25mm in length, and are strongly pleochroic, showing green, bluish-green, and yellowish-green when viewed from different directions.