A type of silica-rich dirt which is soft, fine-grained, porous, light-coloured, and composed of the fossilized remains of diatoms, i.e. single-celled, siliceous organisms
Diatomaceous earth is a fine-grained, porous, powdery earth (i.e. soil and dirt, as distinguished from rock and sand). It is soft and light-coloured. It is composed of the fossilized skeletons or remains of diatoms. Diatoms are a major group of microscopic algae and are among the most common types of phytoplankton. Most diatoms are unicellular, although some form chains or simple colonies. A characteristic feature of diatom cells is that they are encased within a unique cell wall made of silica. These walls show a wide diversity in form, some quite beautiful and ornate, but usually consist of two symmetrical sides with a split between them, hence the group name.
Diatomaceous earth forms from the accumulation of the amorphous silica and the remains of diatoms in marine sediments. The particle size of diatomaceous earth ranges from less than 3 micrometers to more than 1 millimeter. Thus, it is often used as a filter or as a mild abrasive such as in toothpaste and metal polishes.
Abbreviation / Acronym: D. E.