metamorphic

Weathered quartz-rich rock, possibly iron-stained quartzite or quartz vein fragment

Mostly quartz (SiO₂), with probable iron-oxide staining and minor feldspar or clay minerals

AI-generated identification · may be incorrect

Tan-brown, rounded and knobby, with a dull to slightly granular luster; likely Mohs hardness about 6.5–7, no obvious cleavage, and specific gravity near 2.6. The surface appears heavily weathered, so mineral identification from the image is limited.

Identified September 16, 2026More metamorphic →

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At a glance

Common name: Weathered quartz-rich rock, possibly iron-stained quartzite or quartz vein fragment
Scientific name: Mostly quartz (SiO₂), with probable iron-oxide staining and minor feldspar or clay minerals
Category: metamorphic
Identified: September 16, 2026
Method: Standard

AI Estimated Value

About $1–$10 as an ordinary unidentified specimen; higher only if testing reveals attractive crystals, unusual mineral inclusions, or provenance.

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 as quartz-rich sediment metamorphosed into quartzite, or as quartz deposited in a vein and later weathered and rounded; age depends on its source geology. Iron oxidation produces the brown coloration.

Uses & applications

Suitable mainly as a curiosity, teaching specimen, or decorative stone; it has little industrial or jewelry value unless fresh, crystalline quartz is exposed.

Geological facts

Quartz-rich rocks commonly resist weathering, leaving rounded residual cobbles. A steel nail should not scratch it, while quartz or a hardened steel file may scratch or abrade the surface.

Field identification & locations

Look for abundant translucent grains, glassy fracture, and strong resistance to scratching; fizzing with dilute acid would suggest carbonate instead, though none is evident. Common in quartz-bearing gravel, veins, and metamorphic terrains worldwide.