This paper is a discussion of the mineral lepidolite. Different aspects of the mineral lepidolite will be discussed here concerning the mineral's symmetry, physical description and distinguishing features, the manner in which the mineral forms and the rocks in which it is found, and important sites in which lepidolite is found. Also to be discussed are lepidolite's scientific importance and economic value, and the origin of the minerals name.
Lepidolite derives its name from the Greek word "lepidos," which means scale. It is called this because of the way in which it occurs in nature, being mostly found in aggregates of small flakes. Lepidolite was also named "scale stone", or "Schuppenstein" by the early German miners. It was from this name that the idea for the Greek word of scale was used to name this mineral (Sinkankas, 1959, p. 501).
Lepidolite is the most common lithium-bearing mineral and occurs usually in pegmatites. Although it is most often found in flakes, it can sometimes be discovered in the form of large tabular crystals. Lepidolite is in the mica group, which in turn belongs to the group of silicates.
The structure and symmetry of lepidolite is, of course, similar to that of a mica. The crystal system is monoclinic, hexagonal and orthorhombic. The space group is C2/m, C2/c or Cm; P3112, P3212, Ccm2l. Z:1 (C2/m, Cm), 2 (C2/c); 3 (P3,12 or P3212); 24 (Ccm2l). The hardness of the mineral is 2-1/2 to 3, and the density is 2.8-3.3 (Meas.). Lepidolite is considered to be soft to semi-hard. It has light, perfect basal cleavage into flexible and elastic lamallae (MacDonald Encyclopedia..., 1983, p. 231). Twinning in lepidolite is rare.
Lepidolite has been found to be a polymorphic unit of cells, which have been recorded as single-layered monoclinic, six-layered monoclinic, and three-layered hexagonal (Deer and Zusman, 1962, p. 86). The cleavage is (001) perfect, micaceous; (110) imperfect; and (010)...