fossil

Fossil coral or shell fragment

Indeterminate calcareous fossil; likely aragonite or calcite (CaCO₃)

AI-generated identification · may be incorrect

Cream-colored, irregularly rounded, layered/lamellar texture with dull to pearly luster; likely Mohs hardness 3–4, porous, and nonmetallic. Exact identification requires a close view of internal structure and an acid test.

Identified August 25, 2026More fossil →

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Physical properties

Formation & geological history

A marine organism’s calcium-carbonate skeleton or shell was buried in sediment and preserved through diagenesis, commonly during the Paleozoic–Cenozoic. Weathering or preparation may have exposed its layered form.

Uses & applications

Primarily a teaching or collectible specimen; fossilized coral and shells are sometimes used in cabochons and decorative objects, but this small fragment has little industrial value.

Geological facts

Effervesces in dilute hydrochloric acid if calcitic; aragonitic material may recrystallize to calcite over geologic time. The visible concentric, petal-like layers could also represent a small fossil shell or bryozoan fragment.

Field identification & locations

Look for repeated biological geometry, growth lines, pores, or chambers rather than crystalline grains; compare with coral, bivalve, and bryozoan fossils. Common in marine sedimentary rocks worldwide, but locality is essential for confident identification.