metamorphic

Weathered quartz-rich metamorphic rock (probable quartzite)

Quartzite; predominantly microcrystalline quartz (SiO₂), with possible mica, feldspar, and iron-oxide impurities

AI-generated identification · may be incorrect

Hardness about 7, gray to tan, dull-to-slightly sparkling luster, massive granular texture, no obvious cleavage, and typically high specific gravity around 2.6. The rusty yellow-brown areas likely reflect iron-oxide weathering or attached altered material.

Identified August 10, 2026More metamorphic →

Explore Weathered quartz-rich metamorphic rock (probable quartzite) in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

At a glance

Common name: Weathered quartz-rich metamorphic rock (probable quartzite)
Scientific name: Quartzite; predominantly microcrystalline quartz (SiO₂), with possible mica, feldspar, and iron-oxide impurities
Category: metamorphic
Identified: August 10, 2026
Method: Standard

AI Estimated Value

About $1–$10 as a common hand specimen; $10–$30 if unusually attractive, locality-labeled, or display quality.

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

Quartzite forms when quartz-rich sandstone is recrystallized under heat and pressure during regional metamorphism; its age depends on the original sandstone and could range from Precambrian to much younger. The surface is strongly weathered and may include a contrasting matrix or coating.

Uses & applications

Used as crushed aggregate, road stone, slabs, wall stone, and occasionally as a decorative or lapidary material; this rough specimen has little jewelry value.

Geological facts

Quartzite commonly breaks across grains rather than around them, producing very hard, sharp fragments. It can be confused with quartz-rich sandstone, but quartzite generally lacks visible pore spaces and resists scratching by steel.

Field identification & locations

Common in metamorphic mountain belts worldwide, including the Appalachians, Alps, Scandinavia, India, and western North America. A steel file should fail to scratch fresh quartz-rich surfaces; acid typically produces no reaction.