GEYSERITE (siliceous sinter) - New Zealand

New Zealand
  
Geyserite is a variety of silica that forms around hot springs and geysers. It has a porous texture and is very light in weight.  

It is deposited as mounds on the adjacent ground, sometimes forming spectacular cascades and terraces.

Geyserite has a variety of textures with tubes and filaments, largely the result of the replacement by silica of organic matter such as microbes or plant material. 

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