sedimentary

Likely weathered limestone or iron-stained sandstone

Calcite-rich limestone (CaCO₃) or ferruginous sandstone; image is insufficient for certain identification

AI-generated identification · may be incorrect

Tan to rusty brown, earthy to dull luster, irregular granular texture, and no visible crystals or cleavage. Limestone has Mohs hardness 3 and fizzes with dilute hydrochloric acid; sandstone is typically hardness 6–7 depending on quartz content.

Identified September 20, 2026More sedimentary →

Explore Likely weathered limestone or iron-stained sandstone 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: Likely weathered limestone or iron-stained sandstone
Scientific name: Calcite-rich limestone (CaCO₃) or ferruginous sandstone; image is insufficient for certain identification
Category: sedimentary
Identified: September 20, 2026
Method: Standard

AI Estimated Value

Typically $0–$5 as ordinary loose fragments; more attractive or locality-labeled specimens may sell for about $5–$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

Likely formed from compacted carbonate sediment or cemented sand, later altered by weathering and iron-oxide staining. Exact age and formation environment cannot be determined visually.

Uses & applications

Common limestone is used for cement, aggregate, building stone, and lime; sandstone is used for construction and paving. These small weathered fragments generally have negligible commercial value.

Geological facts

The brown coloration commonly results from hematite or limonite coatings and staining. A vinegar test may produce weak fizz if calcite-rich, while a fresh scratch surface is more diagnostic than the weathered exterior.

Field identification & locations

Common in sedimentary terrains worldwide, including deserts, marine shelves, river deposits, and road cuts. Test separately: limestone scratches with a steel knife and reacts to acid; quartz-rich sandstone does not fizz and resists scratching.