How to identify Hematoid Quartz

To correctly identify Hematoid Quartz (Quartz with Hematite inclusions (SiO2 + 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 reddish-brown to deep red. The color is due to internal hematite or other iron oxide inclusions, not the quartz itself.

2. 2

   Luster

   How the surface reflects light: metallic, vitreous, dull

   Vitreous (glassy) for the quartz matrix; hematite inclusions can sometimes exhibit a sub-metallic sheen if macroscopic.

3. 3

   Texture

   Grain size and surface feel: coarse, fine, glassy

   Smooth to slightly rough depending on the crystal faces and presence of surface inclusions. Internal texture is crystalline.

4. 4

   Crystal Form

   Shape of visible crystals or crystal faces

   Typically forms as prismatic, hexagonal crystals, often terminated. Can also be found in massive or granular habits. The hematite inclusions can form phantoms, layers, or dispersed specks within the quartz.

5. 5

   Cleavage

   How it breaks: flat cleavage planes vs irregular fracture

   None (quartz). Hematite inclusions do not impart cleavage to the quartz.

6. 6

   Geological Environment

   The rock formation and setting where it occurs

   Hydrothermal veins, pegmatites, metamorphic rocks, and sedimentary environments where silica-rich fluids interact with iron-rich minerals or sediments. 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, white, or gray quartz with red, orange, yellow, or reddish-brown inclusions

Luster

Vitreous

Transparency

Transparent to translucent

Fracture

Conchoidal

Cleavage

None

Composition

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

Physical characteristics

• Crystal Habit: Prismatic, often terminated, massive, granular
• Cleavage Type: None
• Fracture Type: Conchoidal
• Tenacity: Brittle
• Luster Type: Vitreous

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