Siliceous rock
Encyclopedia
Siliceous rocks are sedimentary rocks that have silica (SiO2) as the principal constituent. The most common siliceous rock is Chert
other types include Diatomite. They commonly form from silica-secreting organisms such as radiolarians, diatoms, or some types of sponges
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Chert
Chert is a fine-grained silica-rich microcrystalline, cryptocrystalline or microfibrous sedimentary rock that may contain small fossils. It varies greatly in color , but most often manifests as gray, brown, grayish brown and light green to rusty red; its color is an expression of trace elements...
other types include Diatomite. They commonly form from silica-secreting organisms such as radiolarians, diatoms, or some types of sponges
Sea sponge
Sponges are animals of the phylum Porifera . Their bodies consist of jelly-like mesohyl sandwiched between two thin layers of cells. While all animals have unspecialized cells that can transform into specialized cells, sponges are unique in having some specialized cells, but can also have...
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