Rock Identifier
Stromatolite Fossil (Biogenic sedimentary structure (Stromatolite)) — fossil
fossil

Stromatolite Fossil

Biogenic sedimentary structure (Stromatolite)

AI-generated identification · may be incorrect

Hardness varies around 3-4 on Mohs scale depending on silicification; gray to brown color; dull to earthy luster; layered, mounded, or cabbage-like accretion structures.

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Physical properties

Hardness varies around 3-4 on Mohs scale depending on silicification; gray to brown color; dull to earthy luster; layered, mounded, or cabbage-like accretion structures.

Formation & geological history

Formed by the trapping, binding, and cementation of sedimentary grains by micro-organisms, notably cyanobacteria, in shallow aquatic environments dating from the Precambrian to present.

Uses & applications

Used in educational displays, scientific research into early Earth environments and ancient atmospheres, and as collectible paleontological specimens.

Geological facts

Stromatolites are Earth's oldest known fossils, with some formations dating back over 3.5 billion years and playing a crucial role in oxygenating the early atmosphere.

Field identification & locations

Identify in the field by distinctive concentric laminae or wavy, layered mounding textures in sedimentary limestone or chert outcrops.

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Phylum Echinodermata, Class Crinoidea

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Bioclastic limestone, composed chiefly of calcite (CaCO₃)

sedimentary
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Calcite-rich limestone (primarily CaCO₃); exact identification is uncertain from the image

sedimentary
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Weathered fossil bone fragment (identification uncertain)

Fossilized bone; exact taxon and mineral composition cannot be determined from the image

fossil