Siliceous precipitate was collected from Otake-Hatchobaru geothermal power plants in Japan. The siliceous material is composed essentially of amorphous silica, but the micro-grains (up to 100 μm in size)are usually locatad in-between the spherical particles of amorphous silica(3-15 μm in size)Microorganic, such as bacteria, would play an important role in the precipitation of amorphous silica.
