How to identify Aquamarine

To correctly identify Aquamarine (Beryl (Be3Al2Si6O18)), check each of these features in order. Many rocks and minerals look alike, so cross-reference multiple properties before deciding.

Step-by-step identification

1. 1

   Color

   Overall color and any zoning or banding

   Ranges from pale blue to deep blue-green. The color is typically uniform, but some crystals may exhibit slight pleochroism (appearing different colors when viewed from different angles).

2. 2

   Luster

   How the surface reflects light: metallic, vitreous, dull

   Vitreous (glassy).

3. 3

   Texture

   Grain size and surface feel: coarse, fine, glassy

   Smooth to the touch, due to its hardness and lack of prominent cleavage.

4. 4

   Crystal Form

   Shape of visible crystals or crystal faces

   Hexagonal prisms, often elongated, with flat basal terminations. Striations parallel to the c-axis are common.

5. 5

   Cleavage

   How it breaks: flat cleavage planes vs irregular fracture

   Imperfect basal cleavage, meaning it tends to break along flat planes perpendicular to the long axis, but not easily or cleanly.

6. 6

   Geological Environment

   The rock formation and setting where it occurs

   Granitic pegmatites, hydrothermal veins, and sometimes in metamorphic rocks. Often associated with minerals like quartz, feldspar, muscovite, and sometimes tourmaline or garnet.

Key Facts

Hardness

7.5-8 on the Mohs scale

Specific Gravity

2.68-2.80 g/cm³

Crystal System

Hexagonal

Color

Blue to blue-green

Luster

Vitreous

Transparency

Transparent to translucent

Fracture

Conchoidal to uneven

Cleavage

Imperfect basal {0001}

Composition

Beryllium aluminum cyclosilicate (Be3Al2Si6O18) with trace iron (Fe2+)

Physical characteristics

• Crystal Habit: Prismatic, typically hexagonal, often elongated and striated parallel to the c-axis. Can also be massive.
• Cleavage Type: Imperfect basal {0001}. While present, it is not easily observed and does not typically affect durability in jewelry.
• Fracture Type: Conchoidal to uneven. Breaks with smooth, curved surfaces (conchoidal) or irregular, rough surfaces (uneven).
• Tenacity: Brittle. It can break or chip if subjected to sharp impact.
• Luster Type: Vitreous (glassy).

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