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Geyserite, or siliceous sinter, is a form of 
Mindat with location data
Geysers Opals Sedimentary rocks {{mineral-stub
opal
Opal is a hydrated amorphous form of silica (SiO2·''n''H2O); its water content may range from 3 to 21% by weight, but is usually between 6 and 10%. Due to its amorphous property, it is classified as a mineraloid, unlike crystalline form ...
ine silica
Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , most commonly found in nature as quartz and in various living organisms. In many parts of the world, silica is the major constituent of sand. Silica is ...
that is often found as crusts or layers around hot spring
A hot spring, hydrothermal spring, or geothermal spring is a spring produced by the emergence of geothermally heated groundwater onto the surface of the Earth. The groundwater is heated either by shallow bodies of magma (molten rock) or by c ...
s and geysers. Botryoidal
A botryoidal ( ) texture or mineral habit, is one in which the mineral has an external form composed of many rounded segments, named for the Ancient Greek (), meaning "a bunch of grapes".Adjective form: ''botruoeidēs'' This is a common form f ...
geyserite is known as fiorite
Fiorite is a hydrated silica rock, a form of opal, found in cavities in volcanic tuff. It is a globular, botryoidal or stalactic concretionary form of opal. It has a pearly lustre and forms botryoidal masses. It was named after Santa Fiora, in Ita ...
. Geyserite is porous due to the silica enclosing many small cavities. Siliceous sinter should not be confused with calcareous sinter
Calcareous sinter is a freshwater calcium carbonate deposit, also known as calc-sinter. Deposits are characterised by low porosity and well-developed lamination, often forming crusts or sedimentary rock layers. Calcareous sinter should not be conf ...
, which is made of calcium carbonate.
In May 2017, evidence of the earliest known life on land
''Ambient 4: On Land'' is the eighth solo studio album by British ambient musician Brian Eno. Released in 1982, it was the final edition in Eno's ambient series, which began in 1978 with '' Music for Airports''.
Overview
''On Land'' is a mix ...
may have been found in 3.48-billion-year-old geyserite uncovered in the Pilbara Craton
The Pilbara Craton is an old and stable part of the continental lithosphere located in the Pilbara region of Western Australia.
The Pilbara Craton is one of only two pristine Archaean 3.6–2.7 Ga (billion years ago) crusts identified on the ...
of Western Australia
Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to th ...
.
See also
* * * *Timeline of the evolutionary history of life
The timeline of the evolutionary history of life represents the current scientific theory outlining the major events during the development of life on planet Earth. Dates in this article are consensus estimates based on scientific evidence, main ...
References
External links
Mindat with location data
Geysers Opals Sedimentary rocks {{mineral-stub