How to identify Amazonite

To correctly identify Amazonite (Microcline (variety amazonite)), 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

   Typically blue-green to green, sometimes with white streaks or mottling.

2. 2

   Luster

   How the surface reflects light: metallic, vitreous, dull

   Vitreous (glassy) to pearly on cleavage surfaces.

3. 3

   Texture

   Grain size and surface feel: coarse, fine, glassy

   Often exhibits a granular or massive texture, but can also form well-developed prismatic crystals.

4. 4

   Crystal Form

   Shape of visible crystals or crystal faces

   Usually occurs as anhedral to subhedral masses, or as well-formed triclinic crystals, often twinned (e.g., Carlsbad, Baveno, Manebach twins).

5. 5

   Cleavage

   How it breaks: flat cleavage planes vs irregular fracture

   Perfect cleavage in two directions, nearly at right angles (approximately 90 degrees).

6. 6

   Geological Environment

   The rock formation and setting where it occurs

   Primarily found in granitic pegmatites, but also in some hydrothermal veins and metamorphic rocks.

Key Facts

Hardness

6 to 6.5 on the Mohs scale

Specific Gravity

2.56 to 2.58

Crystal System

Triclinic

Color

Blue-green, green, sometimes with white streaks

Luster

Vitreous to pearly

Transparency

Translucent to opaque

Fracture

Uneven to conchoidal

Cleavage

Perfect in two directions, nearly at 90 degrees

Composition

Potassium aluminum silicate (KAlSi3O8)

Physical characteristics

• Crystal Habit: Prismatic, tabular, massive, granular
• Cleavage Type: Perfect on {001} and {010}, nearly at 90 degrees
• Fracture Type: Uneven to conchoidal
• Tenacity: Brittle
• Luster Type: Vitreous to pearly

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