Quartzite

Physical Properties

Hardness: 7 on Mohs scale; Color: White to light grey; Luster: Vitreous to dull; Crystal structure: Trigonal (granular texture); Cleavage: None; Specific gravity: 2.63-2.65

Formation & Geological History

Formed through the metamorphism of quartz-rich sandstone under high heat and pressure, typically during mountain-building events. Geological age varies significantly by location.

Uses & Applications

Used as crushed stone in construction and road building, in glass manufacturing, and as decorative stone in landscaping or interior design.

Geological Facts

Quartzite is often harder and more durable than the parent sandstone from which it originated. It is resistant to chemical weathering and creates prominent ridges in many mountain ranges.

Field Identification & Locations

Identify by its extreme hardness (scratches glass) and granular, sugary appearance. Found globally in fold mountain belts and shield areas. Collectors value it for its resilience and occasional color variations.

Identified on: 4/28/2026

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