Stromatolite
Image: <a href="//commons.wikimedia.org/wiki/User:Archaeodontosaurus" title="User:Archaeodontosaurus">Didier Descouens</a> (CC BY-SA 4.0)
Mineral NameStromatolite
Chemical FormulaPrimarily CaCO3 and SiO2, with various impurities
Mohs Hardness6.5
Crystal Systemamorphous
Streak Colorwhite to light brown
Cleavagenone
Fractureuneven to conchoidal
Specific Gravity2.7
Colorsyellow, grey, white, brown
Transparencyopaque
Type LocalityWestern Australia, Australia
Mineral GroupBiosedimentary rock (composed primarily of carbonates and silicates)
Usesscientific study, collector specimens, paleontological research
Associated Mineralschert, calcite, dolomite, iron oxides
Rarityuncommon
Description
This specimen displays distinct wavy and layered bands of yellow, grey, white, and brown, characteristic of microbial growth structures. It is a cross-section revealing the internal laminae.
Geological Context
Stromatolites are ancient biosedimentary structures formed by microbial mats, primarily cyanobacteria, in shallow marine environments. They are crucial fossils for understanding early life and the oxygenation of Earth's atmosphere during the Paleoarchean.
