Lepidolite

lepidolite

[lə′pid·əl‚īt]

(mineralogy)

K(Li,Al)₃(Si,Al)₄O₁₀(F,OH)₂ A rose-colored mineral of the mica group crystallizing in the monoclinic system. Also known as lithionite; lithium mica.

McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Lepidolite

 

a mineral of the mica group; by structure, classified as a trioctahedral mica. The approximate chemical composition of lepidolite is KLi_1,5 Al_1,5 [AlSi₃O₁₀] (F, OH), with a Li₂O content varying between 1.23 and 5.90 percent. Principal admixtures include Fe²⁺, Mn, Cs, Rb, and Na. Lepidolite crystallizes in the monoclinic system, forming lamellar crystals and fine-grained scaly masses. The color generally varies from pink to pale violet; colorless varieties are rare. Lepidolite has a hardness of 2.5–3.5 on Mohs’ scale and a density of 2,800–2,900 kg/m³. It occurs in granitic pegmatites in association with pink tourmaline, spodumene, albite, cassiterite, and minerals containing Nb and Ta. Lepidolite is rarely found in greisenized granites and hydrothermal formations. Lepidolite ore is a source of Li and its salts; Cs is sometimes also extracted.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.