Lepidolite
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Lepidolite is a lilac-gray or rose-colored member of the mica group of minerals with chemical formula K(Li, Al)₃(Al, Si, Rb)₄O₁₀(F, OH)₂. It is the most abundant lithium-bearing mineral and is a secondary source of this metal. It is the major... Wikipedia
2V angle: 0° – 58° measured
Birefringence: 0.0290–0.0380
Category: Phyllosilicate
Cleavage: perfect
Color: Pink, light purple, purple, rose-red, violet-gray, yellowish, white, colorless other colors possible but are rare
Crystal class: Prismatic (2/m); (same H-M symbol)
Crystal habit: Tabular to prismatic pseudohexagonal crystals, scaly aggregates and massive