sedimentary
Stromatolite
Biogenic sedimentary rock / Stromatolite
AI-generated identification · may be incorrectHardness of 3 to 4 on the Mohs scale, earthy to dull luster, layered internal structure composed of calcium carbonate, colors range from gray to tan and brown.
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Physical properties
Hardness of 3 to 4 on the Mohs scale, earthy to dull luster, layered internal structure composed of calcium carbonate, colors range from gray to tan and brown.
Formation & geological history
Formed by the trapping, binding, and cementation of sedimentary grains by micro-organisms, primarily cyanobacteria, in shallow water over geological ages.
Uses & applications
Used primarily as educational specimens, decorative display items, and for scientific research into early Earth history.
Geological facts
Stromatolites are among the oldest known fossils on Earth, providing direct evidence of some of the earliest life forms dating back over 3.5 billion years.
Field identification & locations
Easily identified by distinctive domed or layered laminations in sedimentary contexts, commonly found in ancient limestone and dolostone formations worldwide.
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