metamorphic

Quartzite cobble (likely)

Quartzite, composed predominantly of quartz (SiO₂)

AI-generated identification · may be incorrect

Pale cream to white, dull to slightly vitreous; quartz grains appear tightly fused. Hardness about 7 Mohs, no cleavage, irregular fracture; exact composition and specific gravity cannot be confirmed from the photo.

Identified September 26, 2026More metamorphic →

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Physical properties

Formation & geological history

Forms when quartz-rich sandstone is recrystallized under heat and pressure, welding quartz grains together. It can originate in many geological eras and settings.

Uses & applications

Used as a durable building and landscaping stone, aggregate, and occasionally as a decorative or collectible specimen.

Geological facts

Quartzite is typically harder and more resistant to weathering than its sandstone precursor.

Field identification & locations

The rounded, pale cobble is consistent with quartzite, but the image alone cannot rule out another light-colored rock. Look for fused quartz grains and a surface that resists scratching by a steel nail; quartzite occurs worldwide in metamorphic terrains and river gravels.