Mineral Type - Lepidolite

A series between Polylithionite and Trilithionite

A Li-rich mica in, or close to, the so-called Polylithionite-Trilithionite series.
The original lepidolite came from Rožná pegmatite, Žďár nad Sázavou, Vysočina Region, Moravia (Mähren; Maehren), Czech Republic.
The name is sometimes incorrectly applied to lithian muscovite.

Name

Named in 1792 by Martin Klaproth from the Greek words lepidos for "scale" and lithos for "stone".

Physical Properties

Lustre: Sub-Vitreous, Resinous, Greasy, Pearly
Transparency: Transparent, Translucent
Colour: Pink, light purple, light rose red, other colors possible but are rare. Ideally colorless, but frequently occurs in manganese-bearing environments
Streak: White
Hardness: 2½ - 3½ on Mohs scale
Tenacity: Elastic
Cleavage: Perfect {001} perfect
Fracture: Micaceous
Density: 2.8 - 2.9 g/cm3 (Measured) 2.83 g/cm3 (Calculated)

Chemical Properties

Formula: KLi2Al(Si4O10)(F,OH)2 to K(Li1.5Al1.5)(AlSi3O10)(F,OH)2
Elements listed: O, Si
Common Impurities: H,Al,Li,Fe,Ti,Na,Mg,Ge,etc

Age Distribution

Recorded ages: Mesoproterozoic to Cretaceous : 1020 Ma to 126.1 ± 1.1 Ma - based on 8 recorded ages.

Crystallography

Crystal System: Monoclinic

Synonyms

Flower Sugilite, Lavenderine, Lilalite, Lilianthite, Lithia Mica, Lithionglimmer, and Lithionite

Varieties

Cs-rich Lepidolite, Purple Jade, and Rb-rich Lepidolite