sedimentary

Fossiliferous conglomerate

Bioclastic, carbonate-cemented conglomerate (likely limestone matrix)

AI-generated identification · may be incorrect

Rounded pale clasts, probably shell or coral fragments, embedded in a brown granular matrix; typically Mohs 3–4 if calcite-rich, with dull to earthy luster and no consistent cleavage. Calcite may effervesce with dilute hydrochloric acid.

Identified August 16, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed when biological debris and rounded sedimentary fragments accumulated, became cemented, and lithified in a shallow marine, beach, or reef environment. Its exact age cannot be determined from the photograph; age depends on the included fossils and host formation.

Uses & applications

Primarily a teaching, decorative, and collector specimen; carbonate rock may be used as aggregate or ornamental stone, though this small piece has no practical industrial value.

Geological facts

The rounded inclusions may be fossil shell or coral fragments rather than true pebbles, making “fossiliferous limestone” another plausible identification.

Field identification & locations

Look for visible shell walls, growth patterns, or coral pores; a vinegar reaction suggests calcite but is less reliable than hydrochloric acid. Common in former shallow-marine limestone regions worldwide, including Florida, the Caribbean, Mediterranean, and many coastal sedimentary basins.