グスタフ・キルヒホフ
It is associated with other lithium-bearing minerals like spodumene in pegmatite bodies. It is one of the major sources of the rare alkali metals rubidium and caesium. In 1861, Robert Bunsen and Gustav Kirchhoff extracted of lepidolite and yielded a few grams of rubidium salts for analysis, and therefore discovered the new element rubidium.