Lepidolite - Encyclopedia

lepidolite cabochon

    Class : Silicates
    Subclass : Phyllosilicates
    Crystal System : Monoclinic
    Chemistry : K(Li,Al)3(Si,Al)4O10(F,OH)2
    Rarity : Quite common

Lepidolite belongs to the micas group. It is a micas typical of granites and pegmatites rich in sodium and lithium (sodolithic), in which it is frequently associated with albite (cleavelandite) and rubellite, sometimes with cassiterite. It may contain significant quantities of rubidium and cesium (up to 5%) and fluorine (8%). It is a mineral that owes its name to the Greek lepidos (scale), because of its structure in leaflets. Lepidolite forms massive aggregates of fine flakes, more rarely single crystals with hexagonal or rhombic contours that do not exceed 20 cm. Its pink-lilac to purple color is characteristic, but yellow, gray or green specimens are also known. It is an important lithium ore, it can sometimes be used directly in the manufacture of glasses and enamels. It is also an ornamental stone that can be cut in cabochon for jewelery.

Sphere in lepidolite of Brazil
30.00 ct lepidolite cabochon from Brazil
31.40 ct lepidolite cabochon from Brazil
30.00 ct lepidolite cabochon from Brazil

Lepidolite in the World

The most beautiful specimens of lepidolite are squat pseudohexagonal prismatic crystals with a sub-circular section exceeding 20 cm in strong pink hue and constituting superb groups. They come from Xanda, near Virgen da Lapa (Minas Gerais, Brazil) where lepidolite is associated with beautiful blue topaz and cleavelandite. Other Brazilian pegmatites have yielded very good specimens, notably Itatiaia, where centimeter crystals accompany elbaite, and Itinga. Very large crystals also come from Malagasy pegmatites and Muiâne (Mozambique). In the USA, we can mention the Californian pegmatitic district of Pala-Ramona-Mesa Grande which has delivered magnificent crystals with rubellite, and that of Maine (Auburn, Mount Mica, etc...).

Lepidolite in France

In France, the pegmatites of Saint-Sylvestre (Limousin) gave beautiful topaz crystals implanted on magnificent pink lamellar aggregates of lepidolite. This mineral is also very abundant in the leucogranite of Echassières (Allier), but in unaestetic specimens.

Fakes and scams

No fake inventories for this species.

Hardness : 2.5 to 3.5
Density : 2.8 to 2.9
Fracture : Micaceous

Streak : White

TP : Translucent to transparent
IR : 1.551 to 1.587
Birefringence : 0.029 to 0.038
Optical character : Biaxial -
Pleochroism : Low
Fluorescence : Sometimes green

Solubility : Acids

Magnetism : Paramagnetic
Radioactivity : None