Lepidolite

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  Crystal of lepidolite, Brazil
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Crystal of lepidolite, Brazil

Lepidolite (KLi2Al(Al,Si)3O10(F,OH)2) is a lilac or rose-violet colored phyllosilicate mineral of the mica group that is a secondary source of lithium.[1] 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.[2]

[edit] Physical Properties

Color: violet lombo pale pink to white, sometimes gray or yellow.
Luster: vitreous to pearly.
Transparency: transparent to translucent.
Crystal System: monoclinic; 2/m.
Crystal Habits: include tabular to prismatic crystals with a prominent pinacoid termination. Lepidolite forms pseudo-hexagonal "books." Also as micaceous or granular masses.
Cleavage: perfect in one direction perpendicular to the c-axis.
Fracture: uneven.
Hardness: 2.5
Specific Gravity: 2.8+
Streak: white

Associated Minerals: quartz, feldspar, spodumene, amblygonite, tourmaline.

Notable Occurrences: Brazil; Ural Mountains, Russia; California; Tanco Pegmatite, Bernic Lake Manitoba, Canada.

[edit] References

  1. ^ "Manual of Mineralogy, 20th Ed." by Cornelius Hurlbut and Cornelis Klein.
  2. ^ H. Nechamkin, The Chemistry of the Elements, McGraw-Hill, New York, 1968.

See also: List of minerals