Diatomaceous earth (DE) is a naturally occurring, fine, white to off-white powder with a soft, crumbly texture. Its unique properties stem directly from its ancient origins. This versatile material is composed almost entirely of silica, a compound of silicon and oxygen. Understanding where diatomaceous earth comes from involves a journey back millions of years to a time when microscopic life flourished in aquatic environments.
The Microscopic Organisms Behind It
The fundamental source of diatomaceous earth lies in single-celled algae known as diatoms. These microscopic organisms are a major component of phytoplankton found in both freshwater and marine environments. Diatoms are distinguished by their intricate cell walls, called frustules, which are composed almost purely of transparent, opaline silica. These “glass houses” provide structural support for the diatom cells.
When diatoms die, their organic material decomposes, but their durable silica frustules resist degradation. These minute, porous shells accumulate. The unique patterns and shapes of these frustules vary by diatom species, and these preserved shells are the building blocks that ultimately form diatomaceous earth. Diatoms have been abundant in aquatic ecosystems for at least 190 million years, with fossil evidence dating back to the Early Jurassic period.
Formation Over Millennia
The geological process of diatomaceous earth formation begins as vast numbers of these silica frustules settle to the bottom of bodies of water after diatoms die. This continuous accumulation, often mixed with other sediments, creates layers of diatomaceous ooze. Over immense spans of time, typically millions of years, these layers become deeply buried.
Compaction from the weight of overlying sediments and diagenesis, which are physical and chemical changes occurring after deposition, transform the loose diatomaceous ooze into solid rock or deposits of diatomaceous earth. This long-term geological process results in distinct deposits, with marine diatomite originating from ancient oceans and freshwater diatomite from former lakes and rivers.
Natural Deposits and Extraction
Significant deposits of diatomaceous earth are found in locations that were once ancient lakebeds or marine environments. These deposits are now often uplifted and accessible near the Earth’s surface. Major producing countries include the United States, China, and Denmark, with other notable deposits in countries like Peru and Turkey. The United States, for example, has large reserves primarily in California, Nevada, Oregon, and Washington.
Extraction of diatomaceous earth typically involves open-pit mining, where overburden, or overlying earth, is removed to expose the diatomite layers. Heavy machinery is used to clear this material and then extract the diatomite itself. Once mined, the crude diatomite is transported to processing facilities. There, it undergoes primary processing steps like crushing, drying, and milling to produce the fine powder known as diatomaceous earth.