How to identify Prasiolite

To correctly identify Prasiolite (Green Amethyst (Quartz variety)), 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

   Pale yellowish-green to deep green. The color is generally uniform, but can sometimes show subtle zoning.

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 when polished; rougher in its natural crystal form.

4. 4

   Crystal Form

   Shape of visible crystals or crystal faces

   Typically occurs as prismatic hexagonal crystals, often terminated with rhombohedral faces. Can also be found in massive or granular forms.

5. 5

   Cleavage

   How it breaks: flat cleavage planes vs irregular fracture

   None (conchoidal fracture).

6. 6

   Geological Environment

   The rock formation and setting where it occurs

   Natural prasiolite is found in hydrothermal veins, pegmatites, and volcanic rocks where amethyst has been subjected to natural heating. Artificially produced prasiolite originates from amethyst-bearing deposits.

Key Facts

Hardness

7 on the Mohs scale

Specific Gravity

2.65 g/cm³

Crystal System

Trigonal

Color

Green

Luster

Vitreous

Transparency

Transparent to translucent

Fracture

Conchoidal

Cleavage

None

Composition

Silicon dioxide (SiO2)

Physical characteristics

• Crystal Habit: Prismatic hexagonal crystals, often terminated by rhombohedral faces; also massive or granular.
• Cleavage Type: None, due to its strong covalent bonds.
• Fracture Type: Conchoidal, producing smooth, curved surfaces resembling broken glass.
• Tenacity: Brittle
• Luster Type: Vitreous (glassy)

Explore Prasiolite