Naturally occurring amorphous silicic acids of fossil origin, also known as diatomaceous earth or diatomite; purified for chromatographic applications

Compared to silica, kieselguhr has a small surface of low activity → application in partition chromatography; impregnated with various substances (paraffin, silicone oil, undecane) it can be used for reversed phase chromatography

The following grades of kieselguhr are manufactured by Johns-Manville. They are narrowly classified with homogeneous particle size distributions and high purity.