metamorphic

Weathered quartz-rich rock, possibly quartzite or silicified sandstone

Quartzite (mostly SiO₂), with possible iron-oxide staining and minor feldspar/mica

AI-generated identification · may be incorrect

Appears gray-tan, opaque to slightly translucent, with a dull to uneven vitreous luster and granular texture. Quartz-rich material is typically Mohs 7, lacks cleavage, and has specific gravity near 2.65; the image alone cannot confirm exact composition.

Identified September 16, 2026More metamorphic →

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At a glance

Common name: Weathered quartz-rich rock, possibly quartzite or silicified sandstone
Scientific name: Quartzite (mostly SiO₂), with possible iron-oxide staining and minor feldspar/mica
Category: metamorphic
Identified: September 16, 2026
Method: Standard

AI Estimated Value

Typically $1–$10 as an ordinary specimen; attractive polished or well-crystallized pieces may reach $20–$50.

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

Likely formed by metamorphism or silica cementation of a quartz-rich sediment, with later weathering and iron-oxide alteration. Such rocks commonly formed in Precambrian to Paleozoic terrains, though age is not determinable visually.

Uses & applications

Used as crushed aggregate, road stone, building/decorative stone, and occasionally as a lapidary material. This irregular weathered piece has little jewelry value.

Geological facts

The rusty brown patches are likely limonite/goethite coatings or inclusions. A true quartzite usually breaks across grains rather than around them and resists scratching by steel.

Field identification & locations

Common in metamorphic belts and quartz-rich sedimentary formations worldwide, including India, Brazil, the United States, and South Africa. Confirm by testing hardness, streak, acid reaction, and grain boundaries.