Lepidolite
Lithium-bearing Mica (Lepidolite) - member of the Polylithionite-Trilithionite series · Mineral Specimen and Semi-Precious Gemstone
Crystal System
Monoclinic; commonly occurs in massive, scaly, or micaceous aggregates with a basal cleavage
Mineral Group
Silicates (Phyllosilicates); Mica Group
Chemical Formula
K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2
Formation Process
Igneous formation; primarily occurs in granitic pegmatites rich in lithium through magmatic differentiation
About This Crystal
A light purplish-grey to lavender mineral with a distinctively shimmery pearly luster. It typically appears as a dense mass of tiny, overlapping plate-like crystals that reflect light simultaneously.
Physical Characteristics
Color: Pink, purple, or grey; Streak: White; Cleavage: Perfect basal (one direction); Fracture: Uneven; Specific Gravity: 2.8–2.9; Fluorescence: Occasionally pale yellow/cream under UV
Optical Properties
Refractive Index: 1.525–1.587; Birefringence: 0.029–0.038; Biaxial negative; displays a pearly shimmer due to its sheet-silicate structure
Hardness & Durability
Origin Region
Pegmatite districts in Brazil (Minas Gerais), Madagascar, USA (California/Maine), and Zimbabwe
Hardness & Durability
Mohs Hardness: 2.5–3.5; very soft and brittle; unsuitable for most jewelry except protected cabs or beads due to low scratch resistance
Care & Maintenance
Clean only with a soft damp cloth; avoid ultrasonic cleaners, steam, and harsh chemicals. Store separately as it is easily scratched by almost all other gemstones.
Rarity & Value
Relatively common in lithium-rich pegmatites; value is generally low to moderate based on color intensity (deeper purple is preferred) and sparkle
Special Characteristics
High lithium content; 'shimmery' appearance is caused by the alignment of many small mica flakes reflecting light (micaceous sheen)
Lore & History
First described in the late 18th century; traditionally associated with tranquility and emotional balance due to its lithium content (used in modern mood stabilizers); often called the 'Peace Stone' in lore.
Notes
Shimmery light purplish grey