sedimentary
Stromatolite
Biogenic sedimentary rock
Hardness varies around 3 to 4 on the Mohs scale, color typically features reddish-brown, grey, or tan banding, luster is dull to vitreous, cryptocrystalline structure with characteristic wavy layered laminations.
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Physical properties
Hardness varies around 3 to 4 on the Mohs scale, color typically features reddish-brown, grey, or tan banding, luster is dull to vitreous, cryptocrystalline structure with characteristic wavy layered laminations.
Formation & geological history
Formed by the trapping, binding, and cementation of sedimentary grains by micro-organisms, notably cyanobacteria, in shallow water environments, often dating back billions of years in the Precambrian.
Uses & applications
Used primarily as decorative lapidary material, in educational displays, and as highly prized specimens for fossil and rock collectors.
Geological facts
Stromatolites represent some of the oldest records of life on Earth, having played a crucial role in producing the oxygen in Earth's atmosphere through photosynthesis.
Field identification & locations
Easily identified in the field by their distinctive undulating, concentric, or stacked dome-like laminated structures. Found worldwide in ancient marine and lacustrine carbonate rocks.
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