How to identify Hematoid Quartz

To correctly identify Hematoid Quartz (SiO2 with Hematite inclusions), 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, often with distinct patterns or phantoms caused by hematite inclusions. The base quartz can be clear or milky.

2. 2

   Luster

   How the surface reflects light: metallic, vitreous, dull

   Vitreous (glassy) for the quartz, with metallic to dull luster for visible hematite inclusions.

3. 3

   Texture

   Grain size and surface feel: coarse, fine, glassy

   Smooth to slightly rough depending on the crystal faces and the nature of the inclusions. Can be granular in massive forms.

4. 4

   Crystal Form

   Shape of visible crystals or crystal faces

   Typically occurs as prismatic hexagonal crystals, often terminated, or as massive, granular aggregates. Inclusions can form phantoms or layers within the crystal.

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, pegmatites, and sedimentary environments where silica-rich fluids interact with iron-rich solutions. Often found in association with other quartz varieties, feldspars, and various iron minerals.

Key Facts

Hardness

7 on the Mohs scale (for quartz)

Specific Gravity

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

Crystal System

Trigonal

Color

Colorless to milky white quartz with yellow, orange, red, or reddish-brown hematite inclusions.

Luster

Vitreous

Transparency

Transparent to translucent, opaque if inclusions are very dense.

Fracture

Conchoidal

Cleavage

None

Composition

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

Physical characteristics

• Crystal Habit: Prismatic hexagonal crystals, often terminated; also massive, granular, or cryptocrystalline aggregates.
• Cleavage Type: Absent
• Fracture Type: Conchoidal
• Tenacity: Brittle
• Luster Type: Vitreous

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