metamorphic

Weathered quartz-rich metamorphic rock, likely quartzite

Quartzite; predominantly quartz (SiO₂), possibly with feldspar, mica, and iron-oxide staining

AI-generated identification · may be incorrect

White to gray, granular and strongly weathered, with dull to weakly glassy luster; quartz hardness is about Mohs 7, no obvious cleavage, and quartzite has an interlocking crystalline texture. The rounded shape and surface discoloration indicate abrasion and weathering.

Identified August 31, 2026More metamorphic →

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At a glance

Common name: Weathered quartz-rich metamorphic rock, likely quartzite
Scientific name: Quartzite; predominantly quartz (SiO₂), possibly with feldspar, mica, and iron-oxide staining
Category: metamorphic
Identified: August 31, 2026
Method: Standard

AI Estimated Value

Approximately $1-$10 as a common loose specimen; usually little collector value unless unusually pure, attractive, or provenance-labeled.

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

Forms when quartz-rich sandstone is recrystallized under heat and pressure, commonly during mountain-building; its exact geological age cannot be determined from the photograph. It may have later been transported as a river or glacial cobble.

Uses & applications

Used as crushed stone, aggregate, road material, riprap, and building or decorative stone; attractive dense pieces may be polished, though this specimen appears ordinary and heavily weathered.

Geological facts

Quartzite commonly resists scratching by a steel knife and typically breaks across quartz grains rather than around them. A vinegar test is generally negative, helping distinguish it from limestone or marble.

Field identification & locations

Common in metamorphic mountain belts and stream gravels worldwide. Confirm by checking that grains are fused, the rock does not fizz with dilute acid, and a steel tool fails to scratch it; the image alone cannot exclude hard sandstone or light-colored granite.