Lepidolite

Lepidolite is the Earth's most common lithium-bearing mineral. It occurs in granite pegmatites, where it is associated with other lithium minerals, such as beryl and topaz. Important as a major source of lithium used to make glass and enamels. It is also a major source of the alkali metals rubidium and cesium.

Species: mica group ♦ Chemistry: K(LiAlRb)3(AlSi)4O10(FOH)2 ♦ Color: pink, purple, lilac ♦ Cleavage: perfect basal cleavage in one direction ♦ Fracture: micaceous ♦ Transparency: transparent, translucent ♦ Luster: sub-vitreous, resinous, greasy, pearly ♦ Crystal System: monoclinic, prismatic ♦ Moh's Hardness: 2.5-4 ♦ Localities: Brazil, Madagascar, Canada, Russia, USA.