Rock Identifier
Fossiliferous limestone pebble (Calcite-rich limestone (primarily CaCO₃), with possible fossil or fossil-fragment patterns) — sedimentary
sedimentary

Fossiliferous limestone pebble

Calcite-rich limestone (primarily CaCO₃), with possible fossil or fossil-fragment patterns

AI-generated identification · may be incorrect

Tan-brown, rounded pebble with a dull, weathered surface and pale reticulated markings that may be fossil traces or mineral-filled cracks. Limestone is typically Mohs 3, calcite has trigonal crystal structure and rhombohedral cleavage, and it effervesces in dilute acid; specific gravity is about 2.7.

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Physical properties

Tan-brown, rounded pebble with a dull, weathered surface and pale reticulated markings that may be fossil traces or mineral-filled cracks. Limestone is typically Mohs 3, calcite has trigonal crystal structure and rhombohedral cleavage, and it effervesces in dilute acid; specific gravity is about 2.7.

Formation & geological history

Likely formed from carbonate sediment and biological debris that lithified on an ancient seafloor, then weathered and rounded by transport. The image alone cannot determine its geological age.

Uses & applications

Common limestone is used in cement, aggregate, and building stone; this small pebble is mainly suitable for collecting or display.

Geological facts

The pale network could also be weathering or mineral veining, so fossil identification is uncertain from the photograph alone.

Field identification & locations

Look for shell or coral structures and test a fresh surface with dilute acid for fizzing; limestone occurs widely in sedimentary regions worldwide.

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