igneous or metamorphic

Quartz-rich rock fragment, possibly granite or quartzite

Primarily quartz (SiO₂), with possible feldspar and iron-oxide staining

AI-generated identification · may be incorrect

Hardness about 7 for quartz; pale gray-white, coarse and granular, with a brown rusty coating or weathered outer surface. Vitreous to dull luster; no obvious cleavage, and likely high silica content.

Identified August 12, 2026More igneous or metamorphic →

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At a glance

Common name: Quartz-rich rock fragment, possibly granite or quartzite
Scientific name: Primarily quartz (SiO₂), with possible feldspar and iron-oxide staining
Category: igneous or metamorphic
Identified: August 12, 2026
Method: Standard

AI Estimated Value

Typically $1-$10 as an ordinary fragment; up to about $10-$30 if unusually attractive, locality-labeled, or confirmed as a notable mineral specimen.

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

Hardness about 7 for quartz; pale gray-white, coarse and granular, with a brown rusty coating or weathered outer surface. Vitreous to dull luster; no obvious cleavage, and likely high silica content.

Formation & geological history

Probably a natural fragment of quartz-rich igneous or metamorphic rock, formed deep in Earth and later exposed by uplift and weathering; the specimen’s exact age and origin cannot be determined from the photograph.

Uses & applications

Unusual pieces may be kept as teaching or collectible specimens; quartz-rich rock is widely used as aggregate, crushed stone, silica feedstock, and occasionally ornamental stone.

Geological facts

The reddish-brown coloration is consistent with iron oxides such as hematite or limonite coating fractures and weathered surfaces. A glassy interior and resistance to scratching would support quartz identification.

Field identification & locations

Look for granular interlocking crystals, strong resistance to a steel knife, and no reaction to dilute hydrochloric acid; a streak test and close inspection are needed to distinguish quartzite from granite. Common worldwide, especially in quartz veins, mountain belts, and weathered bedrock.