Crystal Elbaite

Chemical Formula

Na(Li,Al)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄

Composition

Basic sodium lithium aluminum boro-silicate
 

Color

Elbaite is one of the most varied minerals in terms of color. Colors include green, red, pink and blue. White, colorless, black, brown, yellow, orange, and purple colors are less common. Crystals are frequently multicolored, containing two or more distinct colors. Some specimens are pleochroic.

Streak

White

Hardness

7.0 - 7.5

Crystal System

Hexagonal

Crystal Forms 
and Aggregates

Usually as elongated prismatic crystals that are heavily striated. Also as short, stubby, prismatic crystals. Most Elbaite crystals have a rounded, triangular cross-section. Seldom in tabular crystals. Aggregates include columnar, radiating, botryoidal, in dense groups of tiny, elongated needles, and in compact masses. Crystals may be curved or warped, and in some cases may have their growth interrupted by host rock with the same crystal appearing in two parts of a matrix.
 

Transparency

Transparent to translucent

Specific Gravity

2.9 - 3.0

Luster

Vitreous

Cleavage

3,2

Fracture

Conchoidal to uneven

Tenacity

Brittle

In Group

Silicates; Cyclosilicates; Tourmaline Group

Striking Features

Color, crystal form, hardness, and deep vertical striations.

Environment

Almost exclusively in granite pegmatites.

Rock Type

Igneous

Popularity (1-4)

1

Prevalence (1-3)

2

Demand (1-3)

1