metamorphic

Rounded quartz-rich pebble, likely quartzite

Quartzite; predominantly microcrystalline quartz (SiO₂), possibly with minor feldspar, iron oxides, or clay minerals

AI-generated identification · may be incorrect

White to pale gray, fine-grained, matte to slightly sugary luster, with diffuse rusty-brown inclusions; quartzite has Mohs hardness about 7, no cleavage, conchoidal to uneven fracture, and specific gravity around 2.6–2.7. Its smooth shape indicates water or beach abrasion.

Identified September 15, 2026More metamorphic →

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At a glance

Common name: Rounded quartz-rich pebble, likely quartzite
Scientific name: Quartzite; predominantly microcrystalline quartz (SiO₂), possibly with minor feldspar, iron oxides, or clay minerals
Category: metamorphic
Identified: September 15, 2026
Method: Standard

AI Estimated Value

About $1–$10 as an ordinary specimen; up to $20–$50 if unusually attractive, large, or locally significant.

Not an official valuation

AI estimate for general interest only — not an appraisal. Actual value depends on condition, provenance, and market demand. Verify with a professional before buying, selling, or insuring.

This identification was generated by AI and may contain errors. Verify important details before relying on them — and never use an AI result to judge whether a specimen is safe to handle. Read the full disclaimer

Physical properties

Formation & geological history

Formed when quartz-rich sandstone was recrystallized under metamorphic heat and pressure, commonly during mountain-building; the exact geological age cannot be determined from the photograph. It was later eroded and rounded in a river, beach, or glacial environment.

Uses & applications

Common quartzite is used as aggregate, road stone, landscaping rock, building stone, and occasionally countertops; attractive pieces are collected but are generally low value.

Geological facts

Quartzite is usually harder and more resistant to weathering than its parent sandstone. Brown spots likely represent iron-oxide staining or minor mineral inclusions.

Field identification & locations

A steel nail should not scratch it, while quartz or a steel file may leave a mark; sandstone grains are not visibly loose, and dilute acid should not fizz unless carbonate cement is present. Common worldwide, especially in mountain belts and gravel deposits.