Biologists know about diatoms, the single-celled plants that form diatomaceous earth, because they are truly the lungs of the earth, in that they produce about ¾ of the world’s new oxygen supply. Materials scientists know about diatom skeletons (called frustules), the tiny, intricate porous opal structures, because they are known to be the strongest naturally-occurring substances.
On August 31, we celebrated Diatomaceous Earth Day to recognize the diatom and the remarkable substance it creates, diatomaceous earth.
Diatomaceous earth, also known as DE, is a sedimentary rock found in large deposits worldwide and mined primarily in the United States, Mexico, Chile, Peru, France, Spain, Denmark, and China. While still being formed today, some of the deposits of diatomaceous earth were formed millions of years ago. Diatomaceous earth deposits are formed as diatoms die and fall to the bottom of bodies of water. Over time, the organic portions of the diatoms are weathered away and the remaining opal frustules form diatomaceous earth. Some of the largest deposits in the U.S. were formed in ancient lakes in California, Nevada, Oregon and Washington, and some large deposits were also formed in oceans and occur along the coasts of North and South America.
Discovered by Peter Kasten in Germany around 1836, DE is known for its absorbency, filtration properties, polishing properties and stabilizing qualities. Long before Kasten’s discovery, though, the world was using diatomaceous earth. Ancient Greeks used it as an abrasive as well as a building material in light-weight bricks, and, even in pre-historic times, diatomite was used in the ice-age cave paintings in France.
Today, DE is one of the most useful and durable substances known. DE sees nearly ubiquitous use in the filtration of liquids, including, beer, wine, water (for swimming), chemicals, food and pharmaceuticals; DE provides the flatting in almost all flat paints; DE prevents blocking in plastic film and when oil is spilled, DE is often the first choice to absorb it. And there are hundreds of other applications for DE with many more yet to be discovered!