How to identify Fire Quartz

To correctly identify Fire Quartz (Hematoid 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

   Ranges from pale yellow, orange, and reddish-brown to vibrant fiery red. The color is due to iron oxide inclusions and can be unevenly distributed, often appearing as streaks, clouds, or phantom layers within the quartz.

2. 2

   Luster

   How the surface reflects light: metallic, vitreous, dull

   Vitreous (glassy) on crystal faces and fractured surfaces.

3. 3

   Texture

   Grain size and surface feel: coarse, fine, glassy

   Typically smooth to slightly rough depending on the crystal habit and presence of surface inclusions. Can be massive or crystalline.

4. 4

   Crystal Form

   Shape of visible crystals or crystal faces

   Hexagonal prisms terminated by rhombohedra. Often found as individual crystals, clusters, or massive forms. Inclusions can form phantom crystals or dense patches within the quartz.

5. 5

   Cleavage

   How it breaks: flat cleavage planes vs irregular fracture

   None. Quartz exhibits conchoidal fracture.

6. 6

   Geological Environment

   The rock formation and setting where it occurs

   Hydrothermal veins, pegmatites, and metamorphic rocks where silica-rich fluids interact with iron-bearing minerals. Also found in sedimentary environments where quartz crystallizes in the presence of iron oxides.

Key Facts

Hardness

7 on the Mohs scale (for quartz)

Specific Gravity

2.65 g/cm³ (for quartz, inclusions may slightly increase it)

Crystal System

Trigonal

Color

Colorless, white, or smoky quartz with red, orange, yellow, or brown inclusions of iron oxides (hematite, limonite, goethite)

Luster

Vitreous

Transparency

Transparent to translucent

Fracture

Conchoidal

Cleavage

None

Composition

SiO2 (quartz) with Fe2O3 (hematite) or FeO(OH)·nH2O (limonite/goethite) inclusions

Physical characteristics

• Crystal Habit: Prismatic, often terminated by rhombohedra; also massive, granular, or cryptocrystalline. Inclusions can form phantom crystals.
• Cleavage Type: None
• Fracture Type: Conchoidal
• Tenacity: Brittle
• Luster Type: Vitreous

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