Quartzite with Hematite

Physical Properties

Hardness: 7 on Mohs scale; Color: Grayish-white with reddish-purple staining; Luster: Vitreous to dull; Crystal structure: Non-foliated, granular; Cleavage: None/Conchoidal fracture.

Formation & Geological History

Formed through the metamorphism of quartz-rich sandstone under intense heat and pressure. The reddish-purple coloration is likely due to the oxidation of iron minerals (Hematite) within the rock matrix. This transformation typically occurs during mountain-building events (orogeny).

Uses & Applications

Used in construction as crushed stone or road ballast, as a refractory material in glassmaking due to high silica content, and occasionally as decorative stone for landscaping.

Geological Facts

Quartzite is so tough that it often survives intense weathering better than the surrounding rocks, frequently forming the tops of ridges and hills. It is often confused with marble, but can be distinguished by its superior hardness.

Field Identification & Locations

Identify in the field by its inability to be scratched by a steel nail and its grainy, sandpaper-like texture that does not rub off. Found globally in ancient mountain belts and shield areas. Collectors value specimens with high-contrast mineral staining.

Identified on: 5/2/2026

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