sedimentary
Stromatolite
Biogenic sedimentary rock / microbialite
AI-generated identification · may be incorrectHardness varies by mineral replacement (typically Mohs 3-5), color ranges from tan, brown, to grey, with a dull to earthy luster and distinctive layered domed structures.
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Physical properties
Hardness varies by mineral replacement (typically Mohs 3-5), color ranges from tan, brown, to grey, with a dull to earthy luster and distinctive layered domed structures.
Formation & geological history
Formed by the trapping, binding, and cementation of sedimentary grains by micro-organisms, principally cyanobacteria, dating back over 3.5 billion years.
Uses & applications
Used primarily in educational displays, scientific research regarding early Earth life, and as unique collector display specimens.
Geological facts
Stromatolites are Earth's oldest known macrofossils and played a crucial role in oxygenating the early atmosphere through photosynthesis.
Field identification & locations
Identify by characteristic undulating, laminated layers in limestone or chert outcrops; commonly found in ancient shallow marine carbonate sequences worldwide.
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