Lepidolite is a lilac -gray or rose-colored member of the mica with formula K(Li,Al,Rb)2(Al,Si)4O10(F,OH)2. It is the most abundant lithium and is a secondary source of this metal. It is a phyllosilicate mineral and a member of the polylithionite-trilithionite series. Lepidolite is part of a three-part series consisting of polylithionite, lepidolite, and trilithionite. All three minerals share similar properties and are caused because of varying ratios of lithium and aluminum in their chemical formulas. The Li:Al ratio varies from 2:1 in polylithionite up to 1.5:1.5 in trilithionite.
Lepidolite is found naturally in a variety of colors, mainly pink, purple, and red, but also gray and, rarely, yellow and colorless. Because lepidolite is a lithium-bearing mica, it is often wrongly assumed that lithium is what causes the pink hues that are so characteristic of this mineral. Instead, it is trace amounts of manganese that cause the pink, purple, and red colors.
It is associated with other lithium-bearing minerals like spodumene bodies. It is one of the major sources of the rare alkali metals and caesium In 1861, Robert Bunsen extracted 150 kg (330 lb) of lepidolite and yielded a few grams of rubidium salts for analysis, and therefore discovered the new element rubidium.
It occurs in granite , in some high-temperature quartz veins, greisens and granites. Associated minerals include quartz , spodumene, columbite and beryl
Notable occurrences include Brazil; Ural Mountains, United States, Manitoba. * Yellow lepidolite from Itinga , Brazil. Size: 6.1 x 4.9 x 3.1 cm * Lavender lepidolite "books" from Himalaya Mine, Mesa Grande District, San Diego County, California , US. Size: 4.8 x 3.9 x 3.5 cm * Lepidolite, Virgem da Lapa , Brazil (size 2.4 x 2.1 x 0.7 cm)