metamorphic

Tumbled quartz-rich stone, likely iron-stained quartzite

Quartzite; predominantly microcrystalline SiO₂ with iron-oxide staining

AI-generated identification · may be incorrect

Hardness about 7 Mohs; tan, cream, gray, and rusty-brown coloration; vitreous to sugary/granular luster; massive, nonfoliated texture with no obvious cleavage. The rounded shape and smooth surface indicate tumbling or natural abrasion.

Identified September 15, 2026More metamorphic →

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At a glance

Common name: Tumbled quartz-rich stone, likely iron-stained quartzite
Scientific name: Quartzite; predominantly microcrystalline SiO₂ with iron-oxide staining
Category: metamorphic
Identified: September 15, 2026
Method: Standard

AI Estimated Value

About $2–$15 as a common tumbled specimen; roughly $20–$75 if unusually patterned, polished, or sold as decorative lapidary material.

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, commonly during mountain-building; its exact geological age cannot be determined from the image. Brown coloration likely comes from hematite or goethite coatings and fractures.

Uses & applications

Used as aggregate, paving and building stone, decorative rock, and occasionally as a lapidary material. This specimen has modest value unless it displays unusually attractive patterning or provenance.

Geological facts

Quartzite is generally more resistant to weathering than its parent sandstone and can preserve faint original bedding or sedimentary textures. Iron staining commonly produces gold, orange, and reddish surface patterns.

Field identification & locations

Identify it by its extreme hardness, granular quartz texture, lack of obvious cleavage, and inability to scratch with a steel knife; quartz should scratch glass. Common in metamorphic mountain belts worldwide, including the Appalachians, Rocky Mountains, and Scandinavian Caledonides.