How to identify Hematoid Quartz

To correctly identify Hematoid Quartz (SiO2 with Fe2O3), 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 red to reddish-brown. Can also exhibit a metallic sheen if specular hematite is present.

2. 2

   Luster

   How the surface reflects light: metallic, vitreous, dull

   Vitreous (glassy) for the quartz, often with a sub-metallic to metallic luster from hematite inclusions.

3. 3

   Texture

   Grain size and surface feel: coarse, fine, glassy

   Typically crystalline, often with well-formed quartz crystal faces. Inclusions can be finely disseminated or form distinct patterns.

4. 4

   Crystal Form

   Shape of visible crystals or crystal faces

   Hexagonal prisms terminated by rhombohedra (for quartz). Hematite inclusions can be anhedral to euhedral within the quartz.

5. 5

   Cleavage

   How it breaks: flat cleavage planes vs irregular fracture

   None (for quartz). Hematite has no distinct cleavage.

6. 6

   Geological Environment

   The rock formation and setting where it occurs

   Hydrothermal veins, pegmatites, metamorphic rocks, and sedimentary environments where iron-rich fluids or sediments interact with silica-rich solutions.

Key Facts

Hardness

7 on Mohs scale (for quartz component)

Specific Gravity

2.65 - 2.69 (for quartz, slightly higher with dense hematite inclusions)

Crystal System

Trigonal (for quartz)

Color

Yellow, orange, red, reddish-brown

Luster

Vitreous to sub-metallic/metallic

Transparency

Transparent to translucent

Fracture

Conchoidal (for quartz)

Cleavage

None

Composition

Silicon dioxide (SiO2) with iron oxide (Fe2O3) inclusions

Physical characteristics

• Crystal Habit: Prismatic, often terminated by rhombohedra; massive, granular. Hematite inclusions can be disseminated, botryoidal, or platy.
• Cleavage Type: Absent
• Fracture Type: Conchoidal
• Tenacity: Brittle
• Luster Type: Vitreous (quartz), sub-metallic to metallic (hematite)

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