Crystal Euclase

Chemical Formula

BeAlSiO₄(OH)

Composition

Basic beryllium aluminum silicate

Color

White, light to deep blue, bluish-green, and yellow. May be color-zoned with lighter and darker blue zones or blue and colorless zones.

Streak

White

Hardness

7.5

Crystal System

Monoclinic

3D Crystal Atlas
(Click for animated model) 

Crystal Forms 
and Aggregates

In distinct prismatic crystals that are often somewhat flattend and have a slanted termination. Crystals are usually striated lengthwise, and are often doubly terminated. Crystals usually form individually; crystal clusters are less common.

Transparency

Transparent to translucent

Specific Gravity

3.0 - 3.1

Luster

Vitreous

Cleavage

1,1;3,2

Fracture

Conchoidal

Tenacity

Brittle

In Group

Silicates; Nesosilicates

Striking Features

Color, crystal habits, and hardness

Environment

In granite pegmatites and metamorphosed mica schists.

Rock Type

Igneous, Metamorphic

Popularity (1-4)

2

Prevalence (1-3)

3

Demand (1-3)

1