sedimentary

Sand Dollar Fossil

Echinoidea (Clypeasteroida)

AI-generated identification · may be incorrect

Hardness: 3 (calcite composition); Color: White, tan, or grey; Luster: Dull/Earthy; Structure: Five-fold radial symmetry (pentamerism); Composition: Calcium carbonate (calcite/aragonite)

Hardness: 3 (calcite composition)
Color: White, tan, or grey
Luster: Dull/Earthy

Identified May 13, 2026More sedimentary →

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Physical properties

Hardness: 3 (calcite composition); Color: White, tan, or grey; Luster: Dull/Earthy; Structure: Five-fold radial symmetry (pentamerism); Composition: Calcium carbonate (calcite/aragonite)

Formation & geological history

Formed through the permineralization of the exoskeleton (test) of a marine echinoderm. They are commonly found in sedimentary limestone or sandstone formations dating from the Cenozoic era to the present day.

Uses & applications

Primarily used for decorative purposes, educational fossil collections, and as souvenirs or jewelry components.

Geological facts

The 'pedal' pattern on the top is actually a series of respiratory pores. In Christian folklore, the five holes are said to represent the wounds of Christ, and the internal structures (teeth) are called 'doves'.

Field identification & locations

Identified by its flat, circular shape and star-shaped pattern. Commonly found on beaches or in coastal sedimentary rock outcrops. Collectors should look for intact specimens without cracks.