metamorphic and igneous rocks

Mixed beach pebbles; likely quartzite, granite, and iron-stained metamorphic rock

Predominantly quartzite (SiO₂), granite (quartz–feldspar–mica), and weathered iron-rich rock

AI-generated identification · may be incorrect

Rounded, water-worn pebbles with earthy brown, gray, cream, and speckled colors; surfaces are mostly dull to glassy. Quartzite is about Mohs 7 with no cleavage; granite is about Mohs 6–7 and has interlocking crystals, while iron oxides create rusty coloration.

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At a glance

Common name: Mixed beach pebbles; likely quartzite, granite, and iron-stained metamorphic rock
Scientific name: Predominantly quartzite (SiO₂), granite (quartz–feldspar–mica), and weathered iron-rich rock
Category: metamorphic and igneous rocks
Identified: August 23, 2026
Method: Standard

AI Estimated Value

Typically $1–$10 per pebble; assorted common beach specimens usually sell for under $20.

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

These are natural sedimentary deposits of older rocks transported and rounded by waves or rivers; the source rocks formed millions to billions of years ago, depending on locality. The image does not provide enough detail for a precise age or species-level identification.

Uses & applications

Commonly used as decorative landscaping stone, aquarium or craft material, and teaching specimens; attractive pieces may be collected but are generally low-value.

Geological facts

The brown pebble likely contains quartz with iron-oxide staining, while the pale speckled pebble resembles granite or granitic gneiss. Rounding and smoothness indicate prolonged abrasion in water or surf.

Field identification & locations

Test suspected quartzite with a steel file or knife: it should resist scratching; granite shows visible quartz, feldspar, and dark mica grains. Exact identification requires a close view, streak, hardness, and locality information.