Crystal Lepidolite

Chemical Formula

K(Li,Al)₃(Si,Al)₄O₁₀(F,OH)₂

Composition

Basic potassium lithium aluminum fluoro-silicate

Color

Pink to purple. Occasionally also light gray and yellow.

Streak

White

Hardness

2.5 – 3

Crystal System

Monoclinic

3D Crystal Atlas
(Click for animated model) 

Crystal Forms 
and Aggregates

Most often as small, scaly crystals in dense aggregates. Also as micaceous masses and groupings, and in tabular, foliated, flaky, and scaly forms. Large crystals, which are in stubby pseudohexagonal form, are much rarer then the other micas. Also found in micaceous rounded ball-shaped aggregates and inmassive form with tiny glittery crystals.
 

Transparency

Transparent to translucent

Specific Gravity

2.8 - 2.9

Luster

Pearly

Cleavage

1,1

Fracture

Uneven

Tenacity

Sectile, Elastic

Other ID Marks

Tendency for small pieces or flakes or peel off.

In Group

Silicates; Phyllosilicates; Mica Group

Striking Features

Flaky habit, crystals, color, sectility, and mode of occurence.

Environment

Lepidolite is restricted to high-lithium granite pegmatites.
 

Rock Type

Igneous

Popularity (1-4)

2

Prevalence (1-3)

1

Demand (1-3)

2