metamorphic

Iron-stained quartz-bearing rock, possibly quartzite or hydrothermal quartz breccia

Quartz (SiO₂) with iron-oxide/hydroxide coatings, likely limonite/goethite; exact host rock uncertain

AI-generated identification · may be incorrect

White to gray granular quartz with rusty red-brown, earthy iron staining; vitreous to dull luster, massive texture, no obvious cleavage, Mohs hardness about 7 for quartz and specific gravity near 2.65. The knobby surface may reflect brecciation or weathered matrix.

Identified September 13, 2026More metamorphic →

Explore Iron-stained quartz-bearing rock, possibly quartzite or hydrothermal quartz breccia 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: Iron-stained quartz-bearing rock, possibly quartzite or hydrothermal quartz breccia
Scientific name: Quartz (SiO₂) with iron-oxide/hydroxide coatings, likely limonite/goethite; exact host rock uncertain
Category: metamorphic
Identified: September 13, 2026
Method: Standard

AI Estimated Value

About $2–$15 for an ordinary hand specimen; $20–$75 if the quartz crystals, breccia texture, or locality are especially attractive or documented.

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 fluids deposited quartz and later oxidized iron minerals stained or replaced the surrounding rock; alternatively, it may be weathered quartzite. Age cannot be determined from the photograph.

Uses & applications

Common material has little commercial value, though quartz is used in glass, ceramics, abrasives, and electronics; attractive pieces may be collected as mineral specimens.

Geological facts

Rusty coloration commonly comes from goethite, limonite, or hematite rather than metallic iron. A steel knife should not scratch the exposed quartz, while quartz can scratch ordinary glass.

Field identification & locations

Common in hydrothermal veins, fault zones, and weathered quartz-rich rocks worldwide, including the western United States, Brazil, Australia, and Europe. Test with a glass-scratch test, streak test, and close inspection for crystalline quartz or metallic sulfides.