Siliceous Sinter
Image: Carl Gusler (CC BY-SA 2.5)
Mineral NameSiliceous Sinter
Chemical FormulaSiO₂·nH₂O
Mohs Hardness5.5
Crystal Systemamorphous
Lusterwaxy
Streak Colorwhite
Cleavagenone
Fractureconchoidal
Specific Gravity2.1
Colorswhite, grey, yellow, orange, brown
Transparencytranslucent
Type LocalityYellowstone National Park, USA
Mineral GroupSilicates
Usesscientific study, geothermal indicators
Associated Mineralsmicroorganisms
Rarityuncommon
Description
The image shows Crested Pool, a vibrant blue hot spring, surrounded by white, textured siliceous sinter deposits. The edges of the pool exhibit orange and brown hues due to thermophilic microbial mats, with steam rising from the boiling water.
Geological Context
Siliceous sinter is an amorphous form of hydrated silica that precipitates from superheated geothermal waters as they cool and degas at the Earth's surface. These deposits are characteristic of active geothermal areas, forming distinctive rims and terraces around hot springs and geysers.
