When diatoms die, their siliceous frustules sink. In some areas the frustules are not incorporated into the bottom sediment because they dissolve as they sink or dissolve while on the sediment surface. If the sediment is composed of over 30% diatom frustules by weight, it would be called a “diatom ooze” or a “siliceous ooze.” These are the sediments that are lithified into the rock known as diatomite.
Diatoms: This image illustrates the frustules of fifty different diatom species. These organisms are microscopic in size, and many of their frustules are a network of tiny pores and openings. This characteristic is what makes diatoms a perfect medium for filtering tiny particles from fluids at water treatment plants, breweries, food processors, chemical plants, and other facilities. Their delicate structure is also a reason why they are very soluble.
