fossil

Fossil Sponge / Horn Coral / Crinoid Stem

Phylum Porifera or Cnidaria fossilized in calcium carbonate / silica

AI-generated identification · may be incorrect

Hardness: 3-4 (if calcite/limestone) or 7 (if silicified); Color: Tan to light brown with weathered white patina; Luster: Dull to earthy; Structure: Asymmetrical cylindrical, mushroom-like, or nodular shape formed by fossilization.

Hardness: 3-4 (if calcite/limestone) or 7 (if silicified)
Color: Tan to light brown with weathered white patina
Luster: Dull to earthy

Identified August 2, 2026More fossil →

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Physical properties

Formation & geological history

Formed during the Paleozoic or Mesozoic eras (e.g., Ordovician to Cretaceous) when marine organisms were buried in sediment and their hard parts were replaced by minerals like silica or calcite through permineralization.

Uses & applications

Collected by fossil enthusiasts, used for educational purposes and paleontology studies.

Geological facts

Fossils of this type are often found in ancient seabeds, recording marine biodiversity from hundreds of millions of years ago when shallow seas covered large parts of continents.

Field identification & locations

Look for distinctive branching, cup-like, or mushroom-like shapes that deviate from normal water-worn pebbles. Commonly found in limestone and sedimentary rock outcrops, stream beds, and gravel bars in regions with marine sedimentary history.