How to identify Spirit Quartz

To correctly identify Spirit Quartz (Amethyst Spirit Quartz (variety of Quartz)), 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

   Varies depending on the primary crystal: typically purple (amethyst), yellow/orange (citrine), or smoky brown/grey (smoky quartz). The druzy layer often has a slightly lighter or more translucent shade of the same color.

2. 2

   Luster

   How the surface reflects light: metallic, vitreous, dull

   Vitreous (glassy) on both the main crystal and the smaller druzy crystals.

3. 3

   Texture

   Grain size and surface feel: coarse, fine, glassy

   Rough, spiky, or 'cactus-like' due to the numerous small crystal terminations covering the main crystal faces.

4. 4

   Crystal Form

   Shape of visible crystals or crystal faces

   Hexagonal prismatic crystals for the main crystal, with smaller, often sub-millimeter to millimeter-sized hexagonal prismatic crystals growing epitaxially on its faces.

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

   Hydrothermal veins and vugs within igneous (e.g., basalt, granite) and metamorphic rocks (e.g., gneiss, schist). Often found in areas with significant volcanic activity or hydrothermal alteration.

Key Facts

Hardness

7 on the Mohs scale (for both primary and secondary quartz crystals).

Specific Gravity

2.65 g/cm³.

Crystal System

Trigonal.

Color

Purple (amethyst), yellow/orange (citrine), smoky brown/grey (smoky quartz), or clear.

Luster

Vitreous.

Transparency

Transparent to translucent.

Fracture

Conchoidal.

Cleavage

None.

Composition

Silicon dioxide (SiO2).

Physical characteristics

• Crystal Habit: Hexagonal prisms, often terminated, with a secondary growth of smaller, outward-pointing hexagonal prisms covering the faces of the larger crystal(s).
• Cleavage Type: Absent.
• Fracture Type: Conchoidal.
• Tenacity: Brittle.
• Luster Type: Vitreous.

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