sedimentary
Fossiliferous Limestone
Limestone with embedded fossil cross-section
Hardness of ~3 (calcite matrix), gray to brownish-gray color, dull luster, massive structure with embedded fossil. The white circular shape is a cross-section of a fossil, likely a shell or stem.
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Physical properties
Hardness of ~3 (calcite matrix), gray to brownish-gray color, dull luster, massive structure with embedded fossil. The white circular shape is a cross-section of a fossil, likely a shell or stem.
Formation & geological history
Formed in marine environments from the accumulation of calcium carbonate and organic remains (shells, coral, algal debris) over millions of years.
Uses & applications
Limestone is used extensively in construction, cement manufacturing, and agriculture. Fossiliferous specimens are collected by hobbyists and educators.
Geological facts
The distinct white ring is a cross-section of a fossilized organism, possibly a crinoid stem or a bivalve/gastropod shell, which got buried in calcareous mud that later lithified into rock.
Field identification & locations
Identify by its reaction (fizzing) with dilute hydrochloric acid. Commonly found in areas that were once shallow ancient seas. For collectors, the presence of distinct fossils adds interest.
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