sedimentary

Rounded fossiliferous limestone or weathered limestone nodule

Likely bioclastic limestone, composed mainly of calcite (CaCO₃); exact identification is limited by the blurry image

AI-generated identification · may be incorrect

Gray-brown, rounded, dull to slightly earthy luster, with irregular pale cream patches that may be shell or calcite fragments. Calcite hardness is Mohs 3, with poor-to-good rhombohedral cleavage; it should effervesce in dilute hydrochloric acid or strong vinegar if exposed calcite is present.

Identified August 19, 2026More sedimentary →

Explore Rounded fossiliferous limestone or weathered limestone nodule 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: Rounded fossiliferous limestone or weathered limestone nodule
Scientific name: Likely bioclastic limestone, composed mainly of calcite (CaCO₃); exact identification is limited by the blurry image
Category: sedimentary
Identified: August 19, 2026
Method: Standard

AI Estimated Value

About $1–$15 as a common loose specimen; potentially $20–$100 if identifiable, fossil-rich, and provenanced.

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 as marine carbonate sediment later lithified into limestone, then rounded by transport or weathering; age cannot be determined visually and may range from Paleozoic to Cenozoic.

Uses & applications

Common limestone is used for cement, aggregate, lime, and building stone; attractive fossil-bearing pieces are collected as specimens, though this example appears primarily of modest educational value.

Geological facts

The pale inclusions could be fossil fragments, veins, or weathered mineral patches; a close inspection or broken surface is needed to distinguish them.

Field identification & locations

Look for visible shell textures, fine carbonate matrix, and acid fizz; a streak test, hand lens, and fresh fracture are useful. Limestone is widespread in former shallow-marine regions worldwide.