metamorphic

Quartz-rich breccia (possibly hydrothermal breccia)

Silicified polymictic breccia; chiefly microcrystalline quartz (SiO₂) with iron oxides and altered rock fragments

AI-generated identification · may be incorrect

Hardness about 6.5–7; mottled pink, cream, gray, brown, and reddish colors; vitreous to dull luster; interlocking quartz matrix enclosing angular fragments, with no obvious cleavage. Iron-oxide staining likely produces the red-brown zones.

Identified September 6, 2026More metamorphic →

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At a glance

Common name: Quartz-rich breccia (possibly hydrothermal breccia)
Scientific name: Silicified polymictic breccia; chiefly microcrystalline quartz (SiO₂) with iron oxides and altered rock fragments
Category: metamorphic
Identified: September 6, 2026
Method: Standard

AI Estimated Value

Typically $5–$30 as a common hand specimen; attractive polished or locality-documented pieces may sell for roughly $40–$150.

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 when silica-rich hydrothermal fluids cemented and replaced fractured host rock; exact age cannot be determined from the photograph and depends on its regional geology.

Uses & applications

Used mainly as a collector specimen or decorative stone when attractive; quartz-rich breccia has limited industrial use compared with uniform quartzite, granite, or jasper.

Geological facts

The angular clasts and contrasting cement are characteristic of brecciation rather than a uniformly crystalline rock. Some specimens may be marketed as jasper or brecciated quartz, though laboratory testing is needed for a precise name.

Field identification & locations

Look for angular fragments in a hard quartz-rich matrix, reddish iron staining, and conchoidal quartz fracture; it commonly occurs in hydrothermal veins, fault zones, and volcanic terrains. A streak, hardness test, and thin-section or X-ray analysis would improve identification.