Diatomite is found in deposits near present-day or ancient bodies of water, because it is composed of the silica shells of water-dwelling diatoms. Diatomite deposits are found throughout the world; major producers include the United States, China, Denmark, and Japan. The United States is the main producer of diatomite, accounting for at least 50 percent of the world’s diatom exports every year.

Salem Press Encyclopedia of Science, 2023. 3p.