sedimentary

Likely graywacke (feldspathic sandstone)

Lithified sandstone, likely a feldspathic or lithic wacke; exact identification requires closer examination

AI-generated identification · may be incorrect

Gray-brown, dull and granular, with poorly sorted sand-sized grains and possible layering. Typical sandstone grains are mainly quartz and feldspar; hardness varies, commonly around 6–7 for the grains, while the cement may be softer.

Identified October 12, 2026More sedimentary →

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At a glance

Common name: Likely graywacke (feldspathic sandstone)
Scientific name: Lithified sandstone, likely a feldspathic or lithic wacke; exact identification requires closer examination
Category: sedimentary
Identified: October 12, 2026
Method: Standard

AI Estimated Value

About $1–$10 for a common hand specimen; higher value would require distinctive features, provenance, or preparation.

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

Formed as sand and rock fragments were deposited, compacted, and cemented; graywacke commonly accumulates in submarine sediment flows. Its age cannot be determined from the photograph.

Uses & applications

Mostly useful as a teaching or collecting specimen; sandstone is also used locally for building stone and aggregate.

Geological facts

The visible rough, granular texture and subtle banding are consistent with a sedimentary rock, but a photograph cannot confirm its grain composition or distinguish it reliably from some fine-grained metamorphic rocks.

Field identification & locations

Look for individual grains, sorting, bedding, and whether the rock breaks across or around grains; a hand lens helps. Similar rocks occur in sedimentary basins and ancient marine deposits worldwide.