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Geyserite, or siliceous sinter, is a form of opaline silica that is often found as crusts or layers around hot springs and 
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Geysers Opals Sedimentary rocks {{mineral-stub
geyser
A geyser (, ) is a spring characterized by an intermittent discharge of water ejected turbulently and accompanied by steam. As a fairly rare phenomenon, the formation of geysers is due to particular hydrogeological conditions that exist only in ...
s. Botryoidal geyserite is known as fiorite. Geyserite is porous due to the silica enclosing many small cavities. Siliceous sinter should not be confused with calcareous sinter, which is made of calcium carbonate.
In May 2017, evidence of the earliest known life on land may have been found in 3.48-billion-year-old geyserite uncovered in the Pilbara Craton of Western Australia.
See also
* * * * Timeline of the evolutionary history of lifeReferences
External links
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Geysers Opals Sedimentary rocks {{mineral-stub