Crystal Aquamarine

Chemical Formula

Be₃Al₂SiO₆

Composition

Beryllium aluminum silicate

Color

Greenish-blue, light blue, sky blue, deep sky-blue

Streak

Colorless

Hardness

7.5 - 8

Crystal System

Hexagonal

Crystal Forms 
and Aggregates

Often as perfect, six-sided hexagons, and usually in individual prismatic crystals. Also in short, stubby crystals, and occasionally in tabular crystals and flattened hexagonal plates. 

The bases of Beryl crystals are usually flat; pyramidal terminations are less common. Also occurs incolumnar aggregates, in distorted etched crystals, and in massive form. Occasionally in drusy or platyaggregates and as bundles of thin, long crystals. Crystals may be striated lengthwise.

Transparency

Transparent to translucent

Specific Gravity

2.6 - 2.9

Luster

Vitreous

Cleavage

3,1 - basal

Fracture

Uneven to conchoidal

Tenacity

Brittle

In Group

Silicates; Cyclosilicates

Striking Features

Crystal habits, color, and associated minerals.

Environment

In granite pegmatites.

Rock Type

Igneous

Popularity (1-4)

1

Prevalence (1-3)

2

Demand (1-3)

1

Quartz, Muscovite, Albite, Orthoclase, Calcite, Schorl, Apatite